The relationships between siblings are the most long-lasting in families. When one of the siblings is a person with intellectual disabilities (ID), this relationship assumes an even more important role since this brother/sister will most likely become the disabled individual’s main caregiver. This pilot study had two aims: to explore the experience as an adolescent or adult sibling of a person with ID and to understand the perceptions of these siblings about quality of life as a sibling and about family quality of life. In-depth interviews were conducted with six siblings. The results showed that the experience of a sibling is positive and the acceptance process is of extreme importance. The domains which, from the sibling perspective, contribute to family quality of life are as follows: Family relationships, Acceptance, Health, Influence of values, Financial well-being, Support from others, and Leisure activities. The implications of these findings for intervention are pointed out.