Born in Drăgășani, his parents were Ion Mihăescu-Stegaru, a lawyer, and his wife Ioana (née Ceaușescu).

Mihăescu's lack of interest in learning, along with the grief provoked by the illness and death of a brother in 1907, account for his mediocre performance and the many years he spent before finishing.

He left in 1916 when Romania entered World War I; in any case, Mihăescu had not passed any exams during two years of study.

His 1928 play Pavilionul cu umbre achieved a resounding success at the National Theatre Bucharest, with Maria Ventura in the lead role.

His novels were Brațul Andromedei (1930), Rusoaica (1933), Femeia de ciocolată (1933), Zilele și nopțile unui student întârziat (1934) and Donna Alba (1935).