Objective: This study tests the hypothesis that integrated family support, in which patients and caregivers are both supported by one professional staff, is more effective in influencing behavior problems and mood of the dementia patient than nonintegrated support, such as psychogeriatric day care only. Design: A quasi-experimental pretest-posttest control group design with matched groups was applied. Setting: Psychogeriatric day-care centers of four community centers and three nursing homes. Participants: Fifty-six dementia patients living at home and their caregivers. Intervention: The patients in the experimental group (n = 33) participated together with their caregivers in an integrated family support program, whereas the patients in the control group (n = 23) received psychogeriatric day care only. Measurements: Behavior problems and mood were observed using standardized behavior observation scales. Results: After 7 months the experimental support program, compared to the regular psychogeriatric day care, showed a large positive effect on the total number of behavior problems (effect size .75), and also specifically on the degree of inactivity (effect size .66) and nonsocial behavior (effect size .61). No effect on mood was found. Conclusions: In influencing the total amount of behavior problems, as well as the degree of inactivity and nonsocial behavior, the integrated family support program proved to be more effective than psychogeriatric day care. Because behavior problems are an important determinant for admission of persons with dementia into a nursing home, integrated family support may contribute to the delay of institutionalization.