Infectious bronchitis virus (IBV) primarily causes a highly infectious bronchitis (IB) disease in commercial chickens. Virus isolation and identification is necessary for diagnosis of the disease. In this study, a total of 6 IBV isolates that isolated from commercial poultry farms in Malaysia were isolated by inoculation in 9 day-old embryonated SPF eggs. After few passages, the embryos showed typical lesions of IB such as stunted and curled cross with feather dystrophy. Then, the 6 IBV isolates were characterized by RT-PCR followed by DNA sequencing of partial S1 gene. The phylogenetic analysis shows that the 6 IBV isolates distinctly clustered into 2 groups. Group I (IBS037A, IBS037B, IBS051 and IBS052) shared 70% similarity with Group II (IBS130 and IBS131).  Group II was genetically closed to QX-like IBV isolates with similarity of 93%. Meanwhile, Group I that formed a distinct branch of the phylogenetic tree has genetic distance ranged from 30% to 36% with 793/B, Mass-type, Taiwan-type and QX-like viruses