This is a research study on "An Assessment of the Effects of Sexual Immorality on the Local Church Assemblies concerning Christ Apostolic Church (C.A.C.), Nyanya District Coordinating Council (DCC), Abuja." The purpose of the study is to expose the effects, causes, and proffer solutions to the sin of sexual immorality in the church and society. A quantitative approach was used to carry out the study and was guided by four research questions on the reality, causes, effects, and possible solutions to sexual immorality. A structured questionnaire designed by the researcher and validated by guardian and counseling experts was distributed to two hundred respondents with one hundred and eighty-four retrieved. The data were collected and statistically analyzed using the simple percentage method of data analysis. It is revealed that sexual immorality is prevalent in the church among church leaders and members alike. Pornographic films and literature, poor parental control, indecent dressing, and peer pressure are discovered to be the causes of sexual immorality the effects on the church and society which are hindrances undermining the spiritual growth of the body of Christ, retards among believers and divorce/destruction of marriages. Teaching, preaching, organizing symposiums, fasting and prayer, decent dressing, and more leadership effort on the issue to proffer solutions to sexual immorality in the local church assembly is called. It is recommended that Church leaders should create awareness of the causes and damaging effects of sexual immorality in the church and society. The church should ban indecent dressing, encourage victims of sexual immorality to speak out and seek help through counseling, and take them through the prayer of deliverance.