Earlier, Uddhav was looking after Saamna (a daily Marathi newspaper) while being actively involved in election campaigning activities. His party won the Brihan Mumbai Municipal Corporation election in 2002 and, thereafter, he was appointed as the party working president in January 2003.
Differences between Thackeray and former Shiv Sena leader Narayan Rane culminated in the expulsion of Rane from the Shiv Sena. Another split in the Sena came when Thackeray and his cousin Raj Thackeray had a falling-out, leading to Raj leaving the Shiv Sena in 2006 to form his own party, the Maharashtra Navnirman Sena.
Uddhav is married to Rashmi Thackeray and has two sons, Aditya and Tejas.
While elder son Aditya is the president of the Yuva Sena, younger son Tejas is believed to be studying in a college in Buffalo City of New York State. Tejas has maintained a very low profile unlike father and elder brother. On 16 July 2012 Uddhav Thackeray was admitted to Lilavati Hospital after he reported chest pain. He underwent an angioplasty and all the three blockages in his arteries were successfully removed.