This study compared the changes in some bio-psychosocial variables (functional independence, nutritional risk, pain, balance and walking, grip strength, general well-being, psychiatric profile, perception of social support, leisure satisfaction, and caregivers' feeling of burden) in four categories of clients during their program at a geriatric day hospital (GDH). The study also evaluated whether or not improvements, if any, were maintained 3 months after discharge. One-hundred-and-fifty-one people, categorized by primary reason for admission, were assessed at the GDH with reliable and valid tools, at admission and at discharge. Three months after discharge, they were reassessed with the same tools. Overall, two categories of clients, stroke / neurological diseases and musculoskeletal disorders / amputations, improved the most. For the gait disorders and falls group, only the functional independence score improved, but not at a clinically significant level. Finally, clients in the cognitive function disorders / psychopathologies group improved the most on their well-being scores and caregivers' burden decreased the most. All gains were maintained up to 3 months after discharge, except for leisure satisfaction. With the exception of clients who attended the GDH because of gait disorders and falls, the improvements and maintenance achieved in each category occurred in the domains where improvement had been hoped for, because of the particular disabilities in question and because of the nature of the GDH services offered.