Administrative data on public shelter utilization among homeless adults from New York City (1 987-1 994) and Philadelphia (1 991-1 994) are analyzed to identify the relative proportion of shelter users by length of stay and rate of readmission, and to identify the characteristics that predict an exit from shelter. Survival analyses reveal that half of adult shelter users will stay fewer than 45 days over a two-year period (combined stays), and that approximately one half of men and one third of women will experience a readmission within two years of the first admission. Results also document the size and relative resource consumption of a long-term sheltered population, finding that 18.2 percent of New York shelter users stay 180 days or more in their first yea6 consuming 53.4 percent of the system days for first-time shelter users. Discrete-time logistic hazard regression analyses reveal that, in general, being older, of black race, having a substance abuse or mental health problem, or having a physical disability, significantly reduces the likelihood of exiting shelter. In both cities, people entering shelter in later years are staying longer, although individuals have shorter episodes on subsequent admissions. The implications of this study for the analysis and management of emergency shelter system utilization are discussed.