The purpose of this study was to analyse prison rehabilitation programs on behaviour reformation of offenders in Kisumu Main Prison, Kisumu County, Kenya. This study employed descriptive research design. A sample of 343 participants was selected from a population of 2400 individuals. Purposive sampling was done in order to select serving prisoners who are engaged in rehabilitation programs on behaviour reformation of offenders. The study utilized questionnaires and interview schedule for data collection. The study found that vocational skills training programs, educational training programs, religious programs, socio-psychological training programs, agricultural training programs had high significant contribution of rehabilitation programs on behaviour reformation of offenders. On the basis of these findings, we conclude that prison rehabilitation programs contribute significantly to the prediction of the behaviour reformation of offenders 5% level of significance. This contribution results from, adequate education facilities and material used to facilitate reformation of offenders as well as tailoring of the programs to enable reformation of offenders. Also, adequate and well trained staff greatly enhances behaviour reformation of offenders. The research recommends rehabilitation programs to enhance behaviour reformation of offenders. It is anticipated that the findings of the current study will provide necessary information useful to the policy makers, prison officers and other stakeholders to enhance behaviour reformation of offenders in rehabilitation centres in Kenya.