Purpose The burden of caregiving for stroke survivors is well known, but the effect of late stroke rehabilitation on the life situation of informal caregivers is unknown. Here, we assessed changes in the life situation of informal caregivers of stroke survivors enrolled in a multimodal intervention trial. Methods This controlled study was a questionnaire-based survey accompanying a three-armed randomized controlled trial of 123 stroke survivors. The care recipients of 106 caregivers who chose to participate were assigned to rhythm-and-music-based therapy (R-MT; n = 37), horse-riding therapy (H-RT; n = 37), or delayed intervention (control group, n = 32). Perceived changes in the life situation of the caregivers were evaluated with the Life Situation among Spouses after the Stroke Event (LISS) questionnaire before randomization, after the 12-week intervention, and 3 and 6 months later. Results After the intervention, the change in the median LISS score was significantly higher among intervention caregivers (1.5 [interquartile range (IQR) 8.8]) than controls (1.5 [IQR 8.8] vs. 0.0 [IQR 12.0], p = 0.036). The improvement was maintained at 3 months (1.5 [IQR 9.0] vs. 0.0 [IQR 10.5], p = 0.039) but not at 6 months (p = 0.284). Conclusion Engaging stroke survivors in multimodal interventions late after stroke appears to have potential to produce gains also in the general life situation of informal caregivers.