Lamb weight at 8 months of age is an important trait in the sheep industry in terms of the onset of puberty around this age; however, knowledge of its effective genetic factors is limited. Therefore, a GWAS using the 50K SNP-Chip was performed on 96 Baluchi sheep to identify the genomic regions associated with 8-month weight. The results of the present study revealed five SNPs on chromosomes 4, 14 and 16 at 5% chromosome-wide significance level, jointly accounting for 0.95% of total genetic variance. Four genes - MTPN, HYDIN, LRGUK and ZFP90 - were found in 50 kb intervals around the significant SNPs, of which MTPN is involved in regulation of skeletal muscle growth. Our results may provide a new vision to identify the genomic regions affecting growth traits in sheep.