Development interventions are often targeted at alleviating community challenges and enhancing livelihood sustainability. However, most intervention efforts usually have short-lived impacts and the projects often degenerate into nothingness. However, community participation has been fingered as one major tool that can ensure the sustainability of community development projects. This study therefore examined the effects of community participation on the sustainability of Community and Social Development Project (CSDP) in Ibadan, Oyo State, Nigeria. Multistage sampling procedure was used to select respondents for the study. Three communities each from the urban, peri-urban and rural areas where CSDP had completed projects were purposively selected for the study. A total of 168 respondents were randomly selected in these communities. Quantitative data on respondents’ age, sex, marital status, household size, community and social characteristics were collected using interview schedule. Data were analysed using frequency counts, percentages and mean, as well as PPMC and Chi-square. The mean age of respondents was 52.8±14.0 years; most (69.6%) of the respondents were males..More than one third of the respondents had tertiary education (43.5%). More than half (53.0%) of the respondents spent 2-5 hours in community development, (56.6%) participated in the project, (52.4%) were indigenes and (55.4%) were community project management committee (CPMC) members. The mean number of years spent in the community was 17.7±15.2 years. The area in which respondents participated most was sharing of idea ( X =2.39). while (55.4%) had high level of participation and (66.1%) indicated that the projects had high sustainability. Significant (p<0.05) relationships exist between project sustainability (r=0.415), age (r=0.281), number of years of formal education (r=0.154, number of hours spent in community (r=0.469) and level of community participation in CSDP. Chi-square shows that significant (p<0.05) associations exist between sex (χ2=9.721), type of community participation (χ2=26.820), status in the community (χ2=41.985) and level of community participation. It was observed that males participated more in community development than females. Also, technical sustainability of projects was found to be low. Therefore efforts should be made to encourage youths to participate in community development.