[1][2][3] He is best known for his acting in Once Upon a Time (1991), Patriarch (1994) After the Rain (2001), Tenth Night (2002), Prophet Joseph (2008–2009) and Shahrzad (2015–2016) television series.

Mahmoud Pakniyyat began stage acting in 1969 and in 1988 he stepped into the world of movies and television.

Pakniyyat has appeared in the series such as Sheikh Mofid (1995), Seasoned Rider (1997), Lighter than Darkness (1999–2002), The Tenth Night (2001), Prophet Joseph (2008), Building No.85 (2010), Behind the Tall Mountains (2012), The Line (2014), The Recluse (2014), and Warm Breath (2015).

He has also acted in a number of movies, including Death Formation (1994), Land of the Sun (1996), The World Upside-Down (1997), The Wrong Guy (1998), The Victorious Warrior (1998), The Deserted Station (2000–2001), City of Chaos (2005), Heartbroken (2008), and Extreme Cold (2009).

Iranian Ministry of Culture and Islamic Guidance has awarded Iran's High Distinction in Art to Pakniyyat.