SummaryEarly onset of menarche has been shown to be associated with breast cancer and ischaemic heart disease. Studies on age at menarche of the Malaysian population are poorly documented. This study aimed to determine the influence of anthropometric and socio-demographic factors on the age at menarche of university students in Malaysia. Data were obtained in 2010–11 from 961 students between the ages of 18 and 25 years from the University of Malaya using stratified sampling, and multiple regression analysis was applied. (...) Sixty-three per cent of students reached menarche at the age of 12 or 13 years, with the mean and median of age at menarche being 12.45±1.17 and 12.01 years, respectively. Menarcheal age was positively associated with height and negatively associated with BMI. Students from urban areas attained menarche earlier than those from rural areas. Students from small-sized families attained menarche earlier than those from larger families. First-born students experienced menarche earlier than those who were seventh-born or later. Obese and overweight students reached menarche earlier than students who were underweight or of normal weight. The variations in age at menarche among the Malaysian ethnic groups were statistically insignificant. The results suggest that heavier and first-born students from small families are more likely to attain menarche earlier than their counterparts. (shrink)