Active trachoma is known to cluster in close contacts, such as mother and child and between siblings, but we do not know the pattern for trichiasis. This cross-sectional study was conducted to determine if there is as much trichiasis as active trachoma within families having close contact. This information will be helpful in designing intervention strategies. Trichiasis patients that presented for surgery were interviewed for the presence or absence of trichiasis in the current nuclear family, their parent/s, brother/s, sister/s, aunt/s or uncle/s. Of the 739 trichiasis patients interviewed, 78% were women. Fourteen percent of trichiasis cases had at least one nuclear family member with the same condition, and 20.0% had other relative/s (parent/s, brother/ s, sister/s, aunt/s or uncle/s) with trichiasis. Trichiasis increases in parallel with the increase in family size of the index case (c2 for trend = 70.6; P < 0.001). Sixty-nine percent of affected nuclear family members of the index cases were female members. In the relative with trichiasis, 92.8% of cases were parents, sisters and brothers of the index cases. Out of these, the majority (70%) were mothers and sisters. The chance of a female trichiasis patient having another relative with trichiasis is 70%. The chance of the mother/sister/s of a male trichiasis patient being trichiasis patients themselves is 80%, while that of the father/brother/s is 20% (c2=21.88; P < 0.001). If a female has trichiasis there is a 70% chance of her mother/sister/s, and 30% chance of the father/ brother/s (c2 = 27.52; P <0.001) also being trichiasis patients.