Breast cancer is one of the commonest cancers among women in Malaysia. The relation between lifestyle practices and the risk of breast cancer in Chinese women aged 21-55 years were assessed using data collected from June to October 2001, via a face-to face interview in a case control study in the Breast Clinics of Kuala Lumpur Hospital and University Malaya Medical Centre. A total of 89 cases with breast cancer were compared with 85 controls without the disease. Our study showed that breastfeeding had an odds ratio of 4.43 after adjustment for confounders. The results add to the evidence of a protective association between breast feeding practices and breast cancer particularly among Chinese women receiving treatment at two government hospitals in the Klang Valley.