Nicolaescu was Romania’s most prolific director with over 40 feature films on his credits, and the most influential personality in the local industry both during the communist era and afterwards, and a popular actor as well. After 1990 he became a political figure, opposing the Romanian New Wave and the renaissance of Romanian cinema.

Nicolaescu was born in 1930 and established himself an engineer background before turning to cinema. He made his first movie, the Romanian-French coproduction Dacii (The Dacs) in 1967. With the support of the political regime he directed historical dramas, adventure films, thrillers and comedies with great success, including Mihai Viteazul (1970), Atunci i-am condamnat pe toţi la moarte (Then I Sentenced Them All to Death, 1972), Nemuritorii (The Immortals,1974), and Nea Mărin Miliardar (1979). He also co-directed (uncredited) Robert Siodmak's Kampf um Rom I (The Last Roman, 1968) and Kampf um Rom II - Der Verrat (1969) with Laurence Harvey and Orson Welles, both of them shot in Romania.

His most popular films comprised the Comisarul Moldovan cycle, based on fictional events during the interwar period when Romania was a kingdom.

He played a key role in the Romanian revolution and launched himself afterwards in a political career. He was a Senator until December 2012 when he retired from politics. He also published five books about the Romanian revolution. His final film, The Last Corrupted Man in Romania (Ultimul corupt din România) was in 8th place on the local admission charts with 13,195 tickets sold in 2012. Poker was in the second position on the local admissions 2010 with 24,234 tickets, and The Surviver (Supravieţuitorul) was the most popular local film of 2008 with 26,772 admissions.