The seemingly ineffective government policies and programmes on the welfare needs of inmates in correctional centres in Nigeria calls for collaboration with NGOs. It is against this backdrop that this study examined NGOs intervention programmes in the rehabilitation process of inmates in correctional centres in Lagos State, Nigeria. Ex-post-facto research design was used for this study. The study population was two correctional homes, their officials and inmates as well as two NGOs and their officials. One hundred and four respondents were selected using purposive and simple random sampling techniques. Thus, 80 inmates, 20 correctional centres officials and 4 NGO officials were the respondents used for this study. Data were collected using structured questionnaire with r= 0.79 and Key Informant Interview (KII) guide. Qualitative data were analysed with the aid of thematic analysis. The study revealed that NGOs’ collaborative interventions positively impacted inmates rehabilitation process in the correctional centres used for this study. Also challenges such as inadequate facilities and funding, low positive synergy between the NGOs and the correctional centres were identified. Based on these recommendations were made.