In the video, Mars is seen dragging an upright piano through Los Angeles, by the time he arrives at the home of his beloved, he discovers she is with another man, so he decides to leave and ends up killing himself.

[5] The original version of "Grenade" had an "uptempo 1960's surf-style sound with jangle pop" and before a live show in New York, Mars "slowed and stripped it down".

[3]"Grenade" was written and produced by the Smeezingtons (Mars, Lawrence, Levine) with additional songwriting by Brown, Kelly, and Andrew Wyatt.

The song was mixed at Larrabee Recording Studios Los Angeles by Manny Marroquin, with Christian Plata and Erik Madrid serving as the assistants.

[22] Spencer Hawk from Little Village wrote that the song "doesn't rely on a hook, and it's mostly Mars' voice with a simple piano riff and a pulsing drum beat".

[19] According to The New York Times music reviewer, Jon Caramanica, the song contains elements of 1980s pop and is accompanied by drums similar to those used by Kanye West.

[24] Both Roberto Mucciacciaro for MTV and Robert Copsey from Digital Spy noticed the similarities with Michael Jackson's "Dirty Diana".

[26] Lyrically, the song contains masochistic themes and tells the story of heartbreak caused by a failed relationship: "Gave you all I had / And you tossed it in the trash".

[19][27][28] The chorus has Mars singing, "I'd catch a grenade for ya," and speaks of unrequited love when the subject girl of his affections "won't do the same".

The critic added, "Mars knows she is bad for him, that's she's preventing him from thinking straight, that he can't actually have her the way he wants, but he still nonetheless has crazy desires for that rush of romantic cocaine that he gets from her.

[32] Tom Gockelen-Kozlowski of The Daily Telegraph complimented "the Kanye West-style genre-bending on Grenade and other tracks that joins the dots between Michael Jackson and Bob Marley.

"[33] Consequence of Sound's Kevin Barber praised the track and Mars, since it "showcases his Michael Jackson-esque vocal range" and it's "heavy, heartbreaking lyrics".

[35] Tony Clayton-Lea of The Irish Times praised "Grenade", saying "the kind of song that JLS and their ilk would chop off their dancing legs for.

"[26] However, Slant's Eric Henderson dismissed its unrealistic lyrics, while AllMusic's Tim Sendra thought the song was "over-the-top"—one of the weaker ones on the album.

[36][37] Spencer Hawk from Little Village criticized the song by calling it "fairly innovative" and notice that the shouting of the lyrics "doesn't feel genuine", however he felt that "It's very safe while being a little risky, and Mars is a solid singer".

[19] The Scotsman dubbed the track a "boy band missile which is a touch desperate in its overwrought overtures to a girl who wouldn't piss on him if he was on fire".

[61] In the first week in the UK, the song topped the chart becoming Mars's third number one with a total of 159 000 copies sold, blocking Lady Gaga's "Born This Way".

[69] In New Zealand, the song spent twenty-nine weeks on the chart and it was number one for three consecutive dates, after taking "The Time (Dirty Bit)" by The Black Eyed Peas from the top spot.

"[90] Mars, sarcastically, replied to rumors related to the use of special effects: "A lot of people think this is a camera trick, but that is a heavy piano.

[88][90] and it involves Mars's efforts to sing to a woman he loves after dragging an upright piano with a rope tied to it through Los Angeles.

[94] James Montgomery of MTV News gave a mixed review on the video, in which he said "after all, it would’ve been easy – and expected – to make something slick, sexy and/or saccharine, a glossy thing where he croons from a rooftop somewhere, removes his shirt, and somehow ends up with the girl.

[104] MTV critique, Jayson Rodriguez, described it as "Lil Wayne delivering a spoken word-style flow, expressing devotion for his love interest".

[105] Nathaniel Drew and Salt Lake Pops Orchestra remixed the song, with the vocal collaboration of Alex Boye and Lindsey Stirling, it was released as a single on July 13, 2012.

[106] Gerrie van Dijk-Dantuma and Michelle Chamuel, contestants on The Voice of Holland and its US version, respectively, sang the theme for the competition and released it digitally through iTunes.

[109] Will Chase, who guest starred as Michael Swift in the TV series Smash, sang the song during the episode titled "Enter Mr. DiMaggio", which originally aired on February 29, 2012.

[117] Mars performed the song at the Bowery Ballroom in New York City on August 25, 2010, with him and his four-piece band dressed in blue tuxedos and black skinny ties.

[121] Additionally, Mars performed on the Late Show with David Letterman, on November 11, 2010, with a soul redemption of "Grenade" accompanied by an all-female string section.

[122] Robbie Draw from website Idolator wrote a positive review, commenting "Bruno Mars hit up the Late Show With David Letterman last night and left a piece of his heart on the stage after turning out an emotional, bluesy rendition of his new single".

[123][124] On January 6, 2011, Mars performed "Grenade" on The Ellen DeGeneres Show with a guitar, "backed by three background singers, a strings section, and pianist".

[131][132] At this time, Mars expressed his apprehension about performing the song because fans have threw dummy grenades on stage, some of which are metal and have posed a safety hazard.