Mărăşescu set two world records over the mile; 4:23.8 minutes on 21 May 1977 in Bucharest, and 4:22.09 minutes on January 27, 1979 in Auckland. The record was broken by Mary Slaney won ran in 4:21.68 minutes a year later in the same city. The current record is 4:12.56.  She briefly held the record in 5000 metres, with 15:41.4 minutes. This record lasted less than four months before being broken by Jan Merrill. 
Mărăşescu was banned for taking anabolic steroids in 1979 for 18 months. After 8 months Mărăşescu was reinstated after IAAF President Adriaan Paulen of the Netherlands said that an 18-month suspension in the steroid case would have kept the women out of the Moscow Olympics, which would have constituted "an extra penalty." He said that the IAAF Council had therefore reinstated them for "humane reasons."