Ovaries surgically removed for fertility preservation from a total of 24 women served as a source of human small antral follicles, including the follicular fluid (FF) and the corresponding granulosa cells (GC). The FF was used to evaluate the intrafollicular concentrations of anti-Müllerian hormone (AMH), inhibin-B, estradiol, progesterone, androstenedione and testosterone. In GC mRNA expression of the AMH type II receptor (AMH-r2) was determined and correlated to the mRNA expression of CYP19 (aromatase), FSH-receptor (FSH-r) and LH-receptor (LH-r) and to the hormonal profiles of the corresponding FF. GC and FF from a total of 64 follicles (diameter of 3-9 mm) were evaluated. Concentrations of AMH in FF showed a highly significant inverse correlation with CYP19 mRNA expression in the corresponding GC and with concentrations of estradiol, progesterone and inhibin-B in the FF. However, a small subgroup of follicles exhibited high levels of AMH simultaneously with relative high levels of CYP19 mRNA. In contrast to AMH, mRNA expression of AMH-r2 was significantly positively correlated to the mRNA expression of FSH-r and CYP 19, but failed to correlate to any other measured parameters. These data confirms an intimate correlation between follicular AMH levels, AMH-r2, FSH-r expression and estradiol secretion in the developing human follicle.