The route runs between the Kioskplaats in the suburb of Hoboken in the South, and the Silsburg cemetery on the Deurne/Wommelgem border in the East.

It was originally built as a part of a vicinal tramway to Schelle and Boom, but was eventually shortened to the itinerary Groenplaats-Hoboken after the opening of railway line 52 In 1936, it was merged with route 3 into an itinerary Merksem-Central station-Groenplaats-South Station-Hoboken, because too many tram routes had their terminus at the Groenplaats at the time, leading to a chaotic situation.

[3] Due to construction works in the Nationalestraat, the route was shortened to the Hoboken-Marnixplaats trajectory on May 2, 2012.

[5][6] On December 6, 2014, the new tram tracks in the Brusselstraat were taken into service, and route 4 now drives between Hoboken and the Nationalestraat via the Bolivarplaats, instead of the Geuzenstraat.

[7] Route 4 is usually identified by a black number 4 on a light blue background.