Neglected tropical diseases (NTDs) are a group of disease conditions that affect the world's poorest people in low- and middle-income countries. NTDs are associated with negative behavioural experiences, including discrimination, rejection and stigmatization, that predisposes those affected to mental health problems. Consequently, researchers have shown profound interest in elucidating the mental health burden associated with NTDs. To address pertinent issues in the burgeoning literature relating to the prevalence, assessment and correlates of mental health problems in NTDs, a systematic review methodology was used. Underpinned by the PRISMA guidelines, a search was conducted of electronic databases, individual journals and bibliographies for articles that were screened and subjected to predetermined inclusion and exclusion criteria. Sixteen articles from African, Asian and South American countries were included in the review. Depression was the most widely investigated mental health issue, followed by stress and anxiety, with prevalence estimates of 7–54%, 8–43% and 19–53%, respectively. The PHQ-9 and GAD-7 and Self-Reporting Questionnaire were the most widely administered mental health screening tools. The major correlates of mental health problems are lower education and economic status and female gender. We recommend multisectoral and multilayered mental health and related interventions to address the increasing burden of mental health in NTDs.