Dorociński was born into a poor family in Milanówek near Warsaw and grew up in a small village Kłudzienko. His father is a smith and his mother is a housewife. He has three brothers, all of them are policemen. As a child he dreamt of becoming a professional football player, but he had to give up the plan after sustaining a major leg injury. He attended the vocational school in Grodzisk Mazowiecki and obtained a machinist certificate. The first person to notice his talent for acting was his history Teacher, who encouraged him to become an actor. In 1993 he enrolled in the Aleksander Zelwerowicz State Theatre Academy.
In his second-year at the State Theatre Academy he was cast as Don Rodrigue in a television adaptation of Le Cid directed by Krystyna Janda. After graduating from the Academy in 1997 he could not find any acting job at first. He worked as a waiter, a bodyguard in a night club and took other Casual jobs until he was offered a post at the Dramatic Theatre in Warsaw. He has also appeared in several plays in the Ateneum Theatre in Warsaw, in which he is currently employed. He played minor roles in multiple television series. His breakthrough was the role in a film directed by Patryk Vega called Pitbull, which brought him Zbyszek Cybulski Award in 2005. He received the Golden Lion award at the Gdynia Film Festival for his role in Róża in 2011. In 2012 he was awarded the Paszport Polityki prize. In 2012-2013 he appeared in a mini-series called Spies of Warsaw (TV Series), co-produced by the BBC and Telewizja Polska.
He is married to scenic designer Monika Sudół. The couple has a son Stanisław (born 2006) and a daughter Janina (born 2008). They also bring up Sudół’s son from a previous relationship, Jakub.
