Theory and clinical practicum in mental health are an important component for students in most nursing curriculum. Some studies have shown that knowledge and confidence in caring for people with mental illness improve after mental health clinical placements while others had contrasting results. Our study examined the relationship between clinical placement, confidence and stigma surrounding mental illness. We undertook a cross-sectional, descriptive correlational study in a sample of 144 undergraduate nursing students in Singapore who had completed their theoretical and clinical practicum in mental health using the Clinical Placement Survey Clinical Confidence Scale and Social Distance Scale. Descriptive, correlations and multiple regression were used to analyse the data. The results showed the mean scores for the social distance scale, clinical confidence scale and clinical placement survey were 19.92 out of 35, 49.29 out of 80 and 103.43 out of 154 respectively. Attitudes toward clinical placement experiences were significantly correlated with both stigmatising attitudes and clinical confidence of which, intentions of working in mental health settings were specifically significantly associated with stigmatising attitudes and attitudes toward clinical placement experiences, with emphasis on greater sense of preparedness, lesser perceived anxiety and greater preference for a future career in mental health nursing. This study highlighted the need to improve current mental health clinical placements to better build nursing students' confidence in caring for mentally ill patients. The interest toward specialising in mental health nursing is still lacking in nursing undergraduate students despite mental health clinical placements.