The objectives were to evaluate the effects of body condition and starch content of postpartum diets on days to first ovulation postpartum. Fifty-three pregnant Holstein cows (BCS at 28 d before the expected calving date: 3.23 ± 0.29; mean ± SD) were fed a common close-up diet with 13.2% starch content, and randomly assigned to either high (26.7%) or low (21.4%) starch diets immediately after calving. Then, all cows were fed the high starch diet from d 24 ± 3 to 42 ± 3 relative to calving. Ovulation was determined using transrectal ultrasonography performed twice weekly starting on d 7 ± 2 after calving until the first ovulation was confirmed. Days to first ovulation were 21.1 ± 2.5, and 22.1 ± 2.2 (LSM ± SEM), respectively for low and high starch diets, and did not differ between treatments (P = 0.78). Body condition score on d −28 relative to expected calving date was negatively correlated with days to first ovulation postpartum in primiparous cows (r = −0.45, P = 0.03), but not in multiparous cows (r = −0.001, P = 0.99; P = 0.01 for interaction). However, there was no difference in days to first ovulation between primiparous cows and multiparous cows (23.0 ± 2.5 vs. 20.6 ± 2.2; P = 0.46), and the interval from calving to first ovulation was not correlated to prepartum BCS change (d −28 to calving; r = 0.21, P = 0.13) or postpartum BCS change (calving to d 24; r = 0.13, P = 0.35) regardless of parity. In addition, there was no relationship between β-hydroxybutyrate concentration in milk at the first milk test and days to first ovulation postpartum (r = −0.29, P = 0.12). In summary, starch content of postpartum diets did not affect the interval from calving to first ovulation, but higher BCS at d-28 relative to expected calving was associated with reduced days to first ovulation postpartum in primiparous cows.