This research thesis aimed at investigating effects of prison overcrowding on the rehabilitation of inmates in Monrovia Central Prison, Liberia. This research study aimed at achieving the following objectives to identify the effectiveness of inmates incarceration on behavior change in Monrovia Central Prison, to examine how prison overcrowding affects the self -sustainability of inmates in Monrovia Central Prison to determine the relevance of vocational education for inmates in Monrovia Central Prison and to establish the relationship between prison overcrowding and vocational education for inmates in Monrovia Central Prison, Liberia. Key informant interview guide was designed and administered to key informants to capture qualitative information. Data from questionnaire were edited and coded then entered in a computer and Statistical Package for Social Scientists (SPSS) program was used to analyze it. The percentage number of respondents according to variables such as; sex, age, objectives and so on were computed and presented using tables. Prison overcrowding and its effects on the rehabilitation of inmates was established using Pearson Linear Correlations Coefficient Statistical Method. Findings revealed that the effectiveness of inmates’ incarceration on behavior change in Monrovia Central Prison has the overall mean or had a value of 2.582 and standard deviation of 66.3%. This implies that inmates are likely to change their behaviors after all they have been jailed and released later on. Findings revealed that the Prison overcrowding affects the self-sustainability of inmates in Monrovia Central Prison  had a mean rated to 2.713 and standard deviation of 0.795 estimated to 79.5%. The researcher concluded that there is a need to explore the Effectiveness of inmates incarceration on behavior change in Monrovia Central Prison.. The second objective was to investigate the extent to which prison overcrowding affects the self-sustainability of inmates in Monrovia Central Prison in Liberia. The study results based on a Pearson’s Correlation revealed that there is a positive and weak relationship between prison overcrowding and rehabilitation programs at Monrovia Central Prison, Liberia The researcher recommended that the government of Liberia should protect prisoners’ physical and mental health. That is to say: the time prisoners spend out of their cells may be increased, with maximum possible time spent in the open air

Keywords: Effects, Inmate, prison overcrowding, rehabilitation of inmate