BACKGROUND Who becomes homeless because of unemployment and what they need are poorly understood. METHODS Four-year time-series study. Homeless characteristics, co-morbid conditions, and needs are correlated with unemployment rates. RESULTS The unemployment rate averaged 6.7% during years 1-2 (N=198) and 11.8% during years 3-4 (N=202). Those presenting during high unemployment worked most recently in clerical positions (10.4% vs. 4.5%, p= .02) and reported unemployment (OR=2.0; 95% CI; 1.07, 3.76) and unaffordable housing (28.7% vs. 15.2%; p<.01) causing homelessness. Those reporting unemployment were more likely to be local residents (OR=2.1; CI=1.01, 4.53), but less likely to have family support (OR=0.4; CI=0.19, 0.87). While comparable proportions reported mental health conditions and received care, more high unemployment individuals reported needing additional care (59.9% vs. 42.9%; p<.001) and that this was necessary for leaving homelessness (58.9% vs. 44.1%; p=.05). CONCLUSIONS High unemployment expands the population vulnerable to homelessness and influences health care needs and social needs.