The Insulin-like growth factor I (IGF-I) has a similar structure with Insulin hormone.This hormone which is transcribed by (IGF-I) gene has an important functional in growth and development of different body tissues. The aim of this study was to investigate the polymorphism of this gene and its relationship with the estimated breeding values of the birth type, birth weight and fleece weight in Raieni Cashmere goats. Breeding values were estimated using records on 13020 Raieni cashmere goats originated from 336 sire and 3617 dams. Univariate animal model was applied for the genetic analysis of the investigated traits using ASReml. To study IGF-1 gene polymorphism, 94 Raieni cashmere goats were selected based on their estimated breeding values for these traits. PCR was used for amplification of 363 bp fragment of exon 4 of IGF-I gene. Thereafter the animal’s genotype was determined using PCR-RFLP. Three genotypes including AA, AB and BB were observed. The frequency of these genotypes was 0.22, 0.65 and 0.13, respectively. No significant associations were found between these genotypes and the investigated production and reproduction traits. The results of this study show that, there is important genetic diversity for the IGF-I in the investigated population but to study the association between the polymorphism of this gene and the studied traits, more data should be used as currently few animals were genotyped.