Objective: To determine the effects of high dose betamethasone on post-Cesarean section HELLP syndrome outcome. Material and Methods: The study was conducted on 65 pregnant women with HELLP syndrome who were planned emergency Cesarean section with a controlled randomized prospective method. Patients were assigned to betamethasone treatment (Group I, n=34) and control groups (Group II, n= 31). In group I, 24 mg intramuscular betamethasone was applied and was repeated 24 hours later. Intramuscular placebo saline was injected in Group II and was repeated 24 hours later. Liver function tests, platelet count and mean arterial pressure were followed-up in the post-Cesarean section period. Results: The mean gestational age was 33 +/- 2.5 weeks in Group I and 33.8 +/- 3 weeks in Group II (p=0.245). Mean arterial pressure before and at 4, 8, 12, and 24 hours were similar. The mean platelet count at admission was 106 32.4x10(3)/mm(3) in Group land 110 +/- 39.7 x 10(3)/mm(3) in Group II (p=0.656). Similarly, the mean platelet counts 12 hours and 24 hours after the Cesarean delivery were not statistically different in between the two groups. The mean platelet count 24 hours after the Cesarean delivery was 103 +/- 51,4x10(3)/mm(3) in Group I and 79 +/- 48x10(3)/mm(3) in Group II (p=0.056). However, the mean platelet count at 48 hours after the cesarean delivery was significantly higher in Group I when compared to Group II (118 +/- 56,9x10(3)/mm(3) and 89 +/- 51,8x10(3)/mm(3) respectively (p=0.042)). Conclusion: High dose betamethasone application in HELLP syndrome results in earlier recovery of platelet counts in the post-Cesarean section period.