A disk drive assembly includes a disk drive, a drive bracket, and a securing member. The disk drive includes a sidewall with a securing hole. The drive bracket receives the disk drive therein. The drive bracket includes a first side panel. The first side panel includes a side panel body substantially parallel to the sidewall and a securing tab extending from the side panel body. A through hole is defined in the side panel body. A securing slot is defined in the securing tab. The securing member includes a member panel, a pivoting portion, and a securing portion. The pivoting portion is pivotably mounted to the first side panel. The member panel includes a positioning tab passing through the through hole to be inserted in the securing hole. The securing portion engages with the securing slot to prevent the securing member from moving away from the first side panel.