AIM: To describe the involvement in relatives of keratoconus (KCN) patients with corneal topography map. · METHODS: A total of 150 siblings of 300 eyes of 75 KCN patients referred to corneal clinic were studied and experienced complete slit-lamp, refraction examinations and topographic cornea maps provided by videophotoker- atography. ANOVA, Fisher exact and Chi-square tests performed to compare of results. · RESULTS: Of 150 siblings, 56% were female and 44% were male with average age of 21 (range 15-39) years. KCN and suspect KCN diagnosed in 12.3% and 6.6% respectively. The central keratometry (CK) was 46.5±4.51 dioptr (D) in KCN and 45.66±1.52D in suspect KCN. Inferior-superior value (I-S) was 3.51±2.5D in KCN and 1.56±1.22D in suspect KCN. In KCN condition the oval pattern was 67.6% (n = 25) and Round pattern detected 32.4% (n =12). In suspect KCN these patterns detected 90% and 10% respectively. Refractive errors in KCN were -7.5 to +1.25 dioptr (-1.25±1.83), in suspect KCN 0.45 to -4.2 dioptr (-0.68±0.76) and in healthy group 2.75 to -7.5 dioptr (-0.6±1.12). Astigmatism was mild in 22.7%, moderate and sever astigmatism in 18.3% in KCN and suspect KCN · CONCLUSION: Increasing KCN condition in healthy siblings of KCN patients shows require to screening plan to early diagnose and cautionly treatment of contact lens in these individuals.