The objective was to evaluate fertility, concentrations of estradiol (E2), progesterone (P4) and antioxidant enzymes in dairy cows fed with organic trace minerals (OTM) supplement during pre- and postpartum. Prepartum Holstein dairy cows (n = 60) were randomly assigned to receive treatments: control or OTM supplemented. Cows were fed ad libitum roughage and dietary concentrate beginning at 21 d before expected calving date and for 21 d after parturition. In OTM supplemented group, cows were supplemented with 5 g/h/d OTM (Bioplex). Cows were timed-AI using a modified Ovsynch as previously described. Serum and follicular fluid (FF) samples were collected via venipuncture and ovum pick-up throughout the experiment for analysis of E2, P4, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) concentrations. Percentage of retained fetal membranes were not different between the groups (P > 0.05), whereas placental expulsion period in control cows was longer than cows fed OTM (13.2 and 6.3 h; P < 0.05). Day to first ovulation and estrus in cows fed OTM occurred sooner than those control cows (P < 0.05). From d 0 to 8 after timed-AI, serum P4 concentrations did not differ between the groups. However, P4 concentrations in OTM cows were greater (P < 0.05) than control cows on d 12 (4.5 vs. 3.7 ng/mL), 15 (5.1 vs. 3.8 ng/mL), 18 (5.2 vs. 3.7 ng/mL), 21 (5.0 vs. 3.0 ng/mL), and 42 (5.6 vs. 3.6 ng/mL). Concentrations of P4 and E2/P4 ratio in FF did not differ (P > 0.05) in small (3–5 mm), medium (6–9 mm) and large (10–20) follicles between the groups. However, FF concentrations of E2 in large follicle in OTM cows were greater when compared with control cows (366.7 and 320.3 ng/mL; P < 0.05). Conception rate did not differ between the groups (P > 0.05). Concentrations of serum SOD and GSH-Px in cows fed OTM were greater (P < 0.05) than those control cows (15.5 vs. 10.6 U/mL and 12.1 vs. 9.9 U/mL). In conclusion, organic trace minerals may provide a suitable approach to enhance fertility in dairy cows.