People with intellectual disabilities (ID) are usually cared for by their own parents, families or informal caregivers. Caring for a person with ID can have a negative impact on caregivers' mental health (burden, depression, anxiety). The main aim of the EDUCA-IV trial was testing the efficacy of a psychoeducational intervention program (PIP) versus standard practice and to see whether the PIP intervention would reduce the caregiver's burden at post-intervention (4 months) and at follow-up (8 months).This was a multi-centre randomised controlled trial including 194 caregivers (96 randomised to PIP, 98 to control condition). PIP intervention consists of 12 weekly group sessions. The control group received treatment as usual. Primary outcomes measured included the Zarit Burden Interview (ZBI). Secondary outcomes were caregivers' mental health (GHQ-28), anxiety (STAI) and depression (CES-D).The decrease of ZBI scores was not significant at 4 months. There was significant decrease in the GHQ scores at 4 and 8 months. CES-D showed relevant results at follow-up. Intention to treat analyses showed similar results.The PIP intervention seems not to be effective reducing burden, but appears to have a positive result on general mental health. The program was well received and valued by caregivers.