AIM: To describe the involvement in relatives of kera-toconus (KCN) patients with corneal topography map. METHODS: A total of 300 eyes of 150 siblings of 75 KCN patients referred to corneal clinic were studied and experienced complete slit-lamp, refraction examinations and topographic cornea maps provided by videophoto-keratography. ANOVA, Fisher exact and Chi-square tests were performed to compare the results.RESULTS: From 150 siblings, 56% were female and 44% were male with average age of 21 (range of 15-39) years old. KCN and suspect KCN diagnosed in 12.3% and 6.6% respectively. The central keratometry (CK) was 46.50±4.51 dioptr(D) in KCN and 45.66±1.52 (D) in suspect KCN. Inferior-superior value (I-S) was 3.51±2.50(D) in KCN and 1.56±1.22 (D) in suspect KCN. In KCN condition the oval pattern was 67.6% (n=25) and round pattern detected was 32.4% (n=12). In suspect KCN these patterns detected were 90% and 10% respectively. Refractive errors in KCN were -7.50 to +1.25D(-1.25±1.83), in suspect KCN 0.45 to -4.2D(-0.68±0.76) and in healthy group 2.75 to -7.5D(-0.6±1.12). Astigmatism was mild in 22.7%, moderate astigmatism in 18.3% in KCN and suspect KCN.CONCLUSION: Increase KCN condition in healthy siblings of KCN patients shows require of screening to early diagnose and cautious treatment of contact lens in these individuals.