Elderly patients often have problems not easily detected during an office visit. We investigated the yield of a home visit by a geriatric nurse specialist as part of an interdisciplinary assessment process. Compared with the findings of an office-based assessment by a general internist, the home visit resulted in up to four new problems (median = 2, mean = 1.7, 95% confidence interval = 1.5-1.8) and one to eight new recommendations (median = 4, mean = 3.6, 95% confidence interval = 3.4-3.9). Twenty-three percent of the problems could have resulted in death or significant morbidity. The most frequent problems related to psychobehavioral difficulties (23.1% of problems involving 38.3% of patients), safety (21.6% of problems involving 35.7% of patients), and caregiver related problems (20.4% of problems involving 33.8% of patients). The most common recommendations related to safety (30.7% of recommendations involving 81.8% of patients), caregiver well-being (19.8% of recommendations involving 52.6% of patients), and social issues (12.7% involving 33.8% of patients). Baseline clinical information did not predict the yield of the home visit in this sample. We conclude that an in-home assessment contributes unique and meaningful information to the geriatric assessment process.