Homeless adults often visit emergency departments and often leave dissatisfied. We tested whether compassionate care, by improving patient satisfaction, can alter subsequent use of emergency services. We identified 133 consecutive homeless adults visiting one inner-city emergency department who were not acutely psychotic, extremely intoxicated, unable to speak English, or medically unstable. Half were randomly assigned to receive compassionate contact from trained volunteers. All patients otherwise had usual care and were followed for repeat visits to emergency departments. We found that rates of use were high, with patients making an average of seven visits a year (0.60 per month). More than a third of all patients made two or more visits within two days of each other. The average number of visits per month after intervention was significantly lower for patients who received compassionate care (0.43 vs 0.65, p = 0.018). Analyses adjusting for each patient's previous rate of use confirmed that compassionate care led to a one third reduction in the number of return visits within one month (95% CI 14 to 40%). Compassionate management of selected homeless adults decreases repeat visits to the emergency department. One explanation is that patients tend to return frequently until they are satisfied with their treatment.