The relationship between city population size and suicide rates rarely has been examined directly, though scholars often assume such a relationship exists based on studies of the association between suicide rates and urbanization (percent of the population living in cities) in various social contexts. In an effort to determine the basic association between suicide rates and city population size, we analyze data for four time points, 1960, 1970, 1980, and 1990, using a random sample of U.S. cities with 10,000 or more population in 1960. In addition, we conduct a time series analysis of change in population size and change in suicide rates over a two decade period. Results indicate that an association between population and suicide is atypical, and even when observed is highly sensitive to methodological specifications. The results call into question the notion that larger city population size is conducive to suicide as well as the assumption that studies of suicide and urbanization can substitute for studies of suicide and city population size.