Purpose: The treatment of severe and chronic substance dependence is challenged by high rates of treatment attrition, highlighting the need to identify factors that hinder treatment retention. The paper aims to discuss this issue. Design/methodology/approach: The present study examined certain neurocognitive and personality traits in relation to treatment retention in a sample of 46 residents of an Australian therapeutic community (TC). The traits examined were previously found to be associated with problematic substance use in non-clinical samples and were also previously shown to differentiate TC clients from social drinkers. The hypothesis was thus that traits that appear to be risk factors for addictions are also likely to impact on TC treatment retention. Findings: Group comparisons of those retained for more than the recommended 90 days vs those who left treatment prematurely showed that after controlling for the influence of depression, those who left treatment prematurely reported significantly higher levels of trait impulsivity, punishment sensitivity and executive cognitive dysfunction. There was a very high rate of alexithymia in the sample (52 per cent), but alexithymia was unrelated to retention. Research limitations/implications: The final sample size was less than planned but reflected the strict participation criteria and temporal limitations of this study. No statistical assumptions were violated and the reliability indices of the scales completed by clients ranged from acceptable to excellent. Another limitation was that dropout cannot be assumed to mean relapse, as the reasons for client dropout were not available. Originality/value: Findings highlight the important roles of trait factors in TC treatment retention in addition to the motivational and interpersonal factors identified in previous work.