The trend of using nonprescription substances for weight-loss management is common. There are several factors associated with the use of nonprescription substances. This study aimed to determine prevalence and factors associated with the use of nonprescription substances for weight-loss management among university students. A cross sectional study was conducted from August until October 2013 among 358 postgraduate students aged 22 - 45 years in Universiti Kebangsaan Malaysia (UKM). A validated self-administered questionnaire was distributed by multistage sampling to the students. The prevalence of using nonprescription substances among university students was 27.9% (n=100). There were significant association between use of nonprescription substances with age (t=2.41, p=0.017), peer influence (t=7.06, p