Many researchers have been indicated that premature hair greying (PHG) may be associated with the multifactorial problem include genetic, trace elements deficiencies and some medical problems such as metabolic disorders. However, the risk factors for premature hair greying are not well known for young adult.This study aimed to determine the risk factors of hair greying in young adult.We conducted a cross-sectional study recruited 100 respondents of a college student at the Universitas Sumatera Utara (USU) with the inclusion criteria: male, less than 25 years old with hair greying and not have skin pigmentation disorders. The questionnaires about greying of hair status, family history of greying and history of family disease were collected by self-report.The age of participants in this study was 20.09 ± 2.01 years (mean ± SD). The mean onset of PHG was 15.23 ± 3.52 years (range: 9 - 22 years). The family history of PHG was 39% with paternal in 262%; maternal in 10%% and both parents in 3%. There was a significant difference between several grey hairs with a family history of PHG P = 0.045. The family history with metabolic disorders; hypertension was 29%, obesity was 25%, and diabetes Mellitus (DM) was 15%. Limitations: Owing to the use of questionnaires, the possibility of recall bias exists. The young female was not evaluated in this study.The family history of PHG and onset of greying are important risk factors associated with PHG of a young adult.