The study compares the experiences of two groups of grandparents, one with a typically developing (TD) grandchild and one with a grandchild with special educational needs and disabilities (SEND). The extent and the kind of grandparents' involvement, the quality of their relationship and the factors that could contribute to the quality were assessed. The study took place in Greece, a country with strong familial ties. 104 grandparents with a TD and 53 with a grandchild with SEND completed a structured questionnaire. The results revealed that grandparents are an important source of support in both groups. They are actively involved in the care and daily life of their grandchild. They are mentors and provide financial support especially to their grandchild with SEND. They enjoy a close relationship with their grandchild but the quality of the relationship was higher in the TD group. The knowledge of the grandchild and a close relationship with the parents were predictors of an emotionally close relationship with the grandchild in both groups. The findings of the study suggest that grandparents are actively involved in the upbringing of their grandchildren. Professionals and community services should recognize their contribution and provide them with skills, support and encouragement.