HLA-DRB1*01:02, 03:01, DQB1*02:01 and DQA1*01:05 alleles were more common in NMO cases compared to controls.DRB1*03:01- DQA1*05:01/3/5-DQB1*02:01, DRB1*01:02-DQA1*01:01-DQB1*05:01 and DRB1*10:01-DQA1*01:04/5-DQB1*05:01 haplotypes were associated with NMO. Here, HLA-DRB1 is linked to neuromyelitis optica.