This study examined barriers to mental health service use and the demographic, medical and psychosocial correlates of these barriers among hematopoietic SCT (HSCT) survivors. A sample of 253 HSCT survivors who were 1 to 3 years posttransplant completed measures of demographic, physical, psychological and social characteristics as well as a newly modified measure of barriers to mental health service use. Only 50% of distressed HSCT survivors had received mental health services. An exploratory factor analysis of the barriers to mental health service use scale yielded four factors: scheduling barriers, knowledge barriers, emotional barriers and illness-related barriers. Patients with higher social constraints (perceived problems discussing the illness experience with significant others) reported higher levels of all four types of barriers. General distress and transplant-related posttraumatic stress symptoms were positively associated with emotional, knowledge and illness-related barriers to mental health service use, whereas physical and functional well-being were inversely associated with these barriers. Having more knowledge barriers and more emotional barriers predicted a lower likelihood of receiving mental health services, as did lower levels of education and general distress. Results suggest that a significant number of HSCT survivors may benefit from education about mental health services that is tailored to individual barriers.