Many factors contribute to the attainment of adult height, including genetic and environmental variables. To assess the relationship between menarcheal age and adult height, measured adult height and recalled menarcheal age were compared by regression analysis in 425 women. The overall regression equation, Height = 158.14 + .4321 (Age) - .1667 (Age-13)2, was significant (P < .003), as was the coefficient for the quadratic term (P = .014). After exclusion of those in whom menarche occurred after age 16, the overall linear regression equation for the remaining 416 patients, Height = 153.95 + .7353 (Age), was still significant (P = .001), but the coefficient for the quadratic term was not. These data suggest that menarcheal age significantly correlates with adult height as an independent variable.