Background: Caregivers experience social, physical and psychological burdens in caring for people with dementia. A study was conducted to assess the efficacy of a multimodal comprehensive care methodology training programme for the family caregivers of people with dementia. Methods: This research was an intervention trial with a quasi-experimental design. A total of 148 family caregivers of people with dementia participated in a multimodal comprehensive care methodology training programme for 6 hours (three times for 2 hours) in 3 months, which was followed by weekly delivery of information via postcard. The care burden of the caregivers was evaluated by the Japanese short version of the Zarit Burden Interview (J-ZBI) before the training, 1 month post-training and 3 months post-training (primary outcome). Each caregiver assessed the symptoms of the people with dementia for whom they provided care with the Behavioral Pathology in Alzheimer’s Disease (Behave-AD) (secondary outcome). Results: A total of 117 family caregivers (79%) were assessed 3 months after training. Over the course of the programme, the care burden significantly decreased from pre-training to 3 months post-training (P < 0.001). The mean care burden scores before, 1 month after, and 3 months after the intervention were 13.3, 10.9 and 10.6, respectively. The mean Behave-AD score of 101 people with dementia (68%) 3 months post-training was lower than that at pre-training, but the difference was not statistically significant (from 13.6 to 11.8, P = 0.005). Conclusions: The multimodal comprehensive care methodology training was associated with a reduction in the care burden of family caregivers. These findings suggest that randomized controlled trials with larger sample sizes are needed. Trial registration UMIN Clinical Trials Registry (UMIN-CTR), UMIN000043245.