Abstract The rates of breast conservation in breast cancer can vary from 75% in highly developed countries where mammographic breast screening programmes has led to detection of small tumours, to 0% in low income countries where there are no early detection programmes and women present with large tumours. Mastectomy is the only choice in countries where there are no radiation therapy facilities, an essential component of breast conservation surgery (BCS). Malaysia is a high middle income country in South East Asia, with population of 31 million and an incidence of breast cancer of 38.9 per 100 000. According to the International Atomic Energy Agency, 78.9% of the population in Malaysia have access to radiation facilities, so access to radiation does not pose a major barrier to BCS. However BCS is only suitable for women who present with small tumours. In Malaysia, 40-60% of women present with Stage 3 and 4 breast cancer, with a mean size of 4 cm. Hence the majority of patients are not suitable for BCS. In a tertiery urban institution, the BCS rate was reported as 22%. Early detection programmes are essential to improve the rates of BCS. However before any early detection programme can be implemented, the public must know the benefits of early detection. Early detection consists of screening for asymptomatic disease by mammography, and downstaging of symptomatic disease. Population-based mammographic screening is not recommended in low and middle income countries, where there have been no randomized controlled trials on mammographic screening to determine effectiveness in reducing breast cancer mortality, and may not be cost-effective in a country with a lower incidence of breast cancer. Malaysia does not have a population-based mammographic breast screening programme; however there are opportunistic programmes where mammograms are provided free of charge. Despite this, several surveys showed that only 5-15% of eligible women in Malaysia had a screening mammogram done. In addition, the same surveys show that women have poor knowledge of the signs and symptoms of breast cancer. Barriers to early detection (and treatment) appear to be at an individual level. A qualitative study on the reasons for late presentation showed that fear of mastectomy, a fatalistic attitude, belief in alternative therapy and poor decision making were seen in women who present late. Deconstructing why women present with advanced cancer and default treatment would provide opportunities for intervention, such as developing materials to assist in decision making and providing culturally sensitive educational materials. An important message is that early detection save lives and save breasts because BCS will be possible. Malaysia is a multi-ethnic country made up of three main races, ie, Chinese, Malays and Indians. Although there is no difference in overall survival between BCS and mastectomy, there are ethnic differences in BCS rates, with the Chinese women opting for mastectomy, with the misconception that more surgery gives them a better change of cure. In conclusion, the most important obstacle to BCS is the large size of the tumour. Psychosocial and cultural barriers to early detection and treatment programmes need to be addressed to reduce the mastectomy rate. Citation Format: Yip CH. IS-3 Overcoming obstacles to breast conservation surgery in Malaysia [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr IS-3.