Purpose To evaluate the correlation between the levels of anti-mullerian hormone and body mass index between obese and non-obese premenopausal women. Methods Serum anti-mullerian hormone levels of women younger than 45 years admitted to our reproductive endocrinology clinic for investigation of infertility were examined in this cross-sectional study. Body mass indices were lower than 30 kg/m2 in 222 patients and equal to or higher than 30 kg/m2 in 37 patients. Levels of antimullerian hormone were analyzed in each group. Blood samples obtained from study subjects were assayed for levels of anti-mullerian hormone, follicle-stimulating hormone, luteinizing hormone, estradiol, prolactin and thyroid stimulating hormone. Results There was no significant difference in terms of mean age between the two groups. There was no statistically significant difference between these two groups in terms of FSH, LH, estradiol and prolactin levels. Antimullerian hormone levels were 3.46 ± 2.79 ng/ml and 3.79 ± 2.93 ng/ml in non-obese and obese participants, respectively. No statistically significant correlation was found between Anti Müllerian Hormone (AMH) levels and BMI levels in either group (P>0.05). Conclusions Body mass index does not have an effect on serum AMH levels in women of reproductive age. Obesity has no association with levels of serum follicle stimulating hormone, luteinizing hormone, estradiol, prolactin and thyroid stimulating hormone. Obesity is unlikely to affect ovarian reserve in the premenopausal age group. © Springer-Verlag 2012.