"Twins have often served science but science has rarely served twins" (Novotny, 1988). Twinship presents specific challenges unique to twins in the realms of physical, emotional, social, interpersonal, and academic trials; twins many times suffer in self-esteem, separation-individuation, and object relations. This paper reviews literature which describes twins, their families, and what has been accomplished in the counseling of twins. The key to healthy twinship lies in self-identity and individuality. Clearly, counselors and therapists may help twins and their families by creating awareness of these attributes found in twinships. The therapist's guide, "Assessment Checklist for Twins and Families of Twins," may serve as a resource in assessment and intervention with twins and their families. The checklist helps to identify characteristics which address twinship. Once therapists identify problem areas, effective interventions may be employed. The Assessment Checklist appears in this report along with a list of resources for twins and their families. Contains 24 references. (RJM)