The main purpose of this study was to examine the prevalence of crimes against property and their causes in the trimester periods of the year 2002-2003 in Nairobi. This is because property crimes have become common problem in Kenya and are as such destruction to the social fabric. To achieve the above objective, Nairobi city was chosen because crime was increasingly becoming a menace and hence a chronic social and more so economic problem. A sample size of two hundred was chosen in order to reduce logistical and analytical problems. This sample was derived from two police divisions, namely; Langata and Industrial Area. A sample frame was drawn and proportionate stratified random sampling was employed. Respondents were asked questions on the prevalence and causes of property crimes. Information gathered from the victims reinforced the fact that they do not report crimes committed against them citing the distance of the police station from the crime scenes and the level of police response. Police statistics too do not reflect the true figures of crimes committed in their stations.