With the objective was analyzing consanguinity on reproductive parameters in a dairy herd Was analyzed records from 4 044 cows Holstein’s breed, totalized 9 355 reproduction records, of a herd of dairy cattle on central coast, to evaluate the main effect of the inbreeding on traits reproduction as: age of pregnancy in heifers and age of first calving, calving interval and length of gestation. The 93,17% of the cows were inbred and the range were from 0,1283% to 31,4722% of inbred, the average inbreeding coefficient of all cows was 5,18%. Effect of inbreeding were estimated by a model that included fixed effects: year-seasons, sire groups, number of calving, age at calving, inbreeding. The inbreeding was included in the model as a classification (six class: 0; 3,125; 6,25; 9,375; 12,50 and >12,50%). The average of the age at pregnancy in heifers was 16,40 months and the age at first ...