Introduction Until today, there is no clear cut off point for age in young breast cancer. Multiple studies have shown that breast cancer among women diagnosed before age of 40 is increasing in trend and have poorer survival rate. Incidence rate among Malaysian breast cancer from the age of 25 and below 40 is also increasing in trend. This is first paper in Malaysia to ascertain the risk factors among young breast cancer in mainland of Penang state, Malaysia Method This is a retrospective study which includes young women diagnosed with breast cancer from 1 st January 2015 until 31 st December 2019, from HSJ cluster hospitals. Inclusion criteria are 40 years old and below at the age of diagnosis of breast cancer, female and complete sociodemographic data. Result This study has shown that 17.07% of women with young breast cancer are age before 31 years old and most are age from 36 to 40 years old. Young age at menarche (12 years old and below), positive family history of breast cancer, use of oral contraceptive pill, breastfeeding history and pregnancy history (parity at least 1 and above) are strongly associated with increased risk of young breast cancer with P-value<0.05. Conclusion This is a small-scale study on young breast cancer patient. Larger population study should be performed to confirm this findings and dwell further on other possible risk factors.