Abstract: Objective: The effect of MYF5 gene polymorphism on body weight was investigated in 100 Friesian bull calves. Methodology: Blood samples were collected from each animal for DNA extraction. The PCR-TaqI digestion of 1190 bp of a fragment of MYF5 gene revealed that, two fragments (983 and 207 bp) for genotype BB, three fragments (1190, 983 and 207 bp) for genotype AB and undigested fragment (1190 bp) for genotype AA. The incidence of MYF5 genotypes and frequencies of alleles were calculated. Results: The AA, AB and BB genotype frequencies in the 100 Friesian bull calves were 0.20, 0.46 and 0.34, respectively and the A and B allele frequencies were 0.43 and 0.57. Statistical analysis indicated that there was highly (p<0.01) significant association between MYF5 genotypes and body weight. The AB genotype was higher in body weight than both BB and AA genotypes. However, there was no significant variation between AB and BB genotypes in the body weight. Conclusion: This study highlights the effect of MYF5/TaqI locus as candidate for body weight in cattle.