The relationship of prior menstrual irregularities and current menstrual status to the bone density of 97 young athletes was determined at seven sites using single- and dual-photon absorptiometry. Menstrual patterns were ranked on a scale of 1 to 9 in terms of their potential adverse affect on bone. Only vertebral density was significantly related to menstrual patterns (r= —.43). Women who had always had regular cycles had higher lumbar densities (1.27 g/cm2) than those with a history of oligomenorrhea/amenorrhea interspersed with regular periods (1.18 g/cm2). The lumbar density of both groups exceeded that of women who had never had regular cycles (1.05 g/cm2). Body weight became more important as a predictor variable as the severity of menstrual irregularities increased. The combination of menstrual pattern and body weight predicted 43% of the total variation in lumbar density. These data suggest that extended periods of oligomenorrhea/amenorrhea may have a residual effect on lumbar bone density.