The present study was undertaken to characterize and estimate cat mortality caused by motor vehicles in Baltimore, Md. Analysis of Municipal Animal Shelter records revealed that the number of dead cats annually removed from Baltimore streets averaged 2,721 over 3 years. The number of cats removed per year was notably constant (range 2,621 to 2,917), with a consistently greater number of animals being picked up during summer months. A map of the location of 634 dead cats removed from city streets showed that areas of highest cat mortality were associated with areas of highest human population density. This map was used to stratify Baltimore into areas of high, medium, and low cat mortality for subsequent stratified random placement of tagged dead cats for the mark-recapture study. One hundred fifteen tagged dead cats were placed on city streets during the course of 1 year, and 50.5% were retrieved by the Municipal Animal Shelter. We estimate over 5,000 free-ranging cats are killed by automobiles/year in Baltimore. Analysis of 212 dead cats removed from city streets showed that the majority were male (63%) and that most animals were sexually intact (90%). At least 20% of the dead animals was previously owned, and few kittens or juvenile cats were found in the sample.