The fire broke out at Mosharaf Composite Textile Mills in Bagher Bazar neighbourhood around 3am, said Md Akteruzzaman Liton, deputy assistant director at Gazipur fire service.
It erupted inside a warehouse on the ground floor, he said.
Seven units from fire stations in Joydebpur, Tongi, Sreepur and Bhaluka are on the scene.
The firemen find it difficult to control the blaze as there are cotton, machinery and inflammable materials inside the warehouse, according to Liton.
No casualties were reported and the cause of the fire is yet unknown.