Sohag Gazi and Abdur Razzak together picked up seven wickets to restrict West Indies for 199 runs, and Bangladesh chased the total with seven wickets in hand.
West Indies won the toss and decided to have a bat against a Bangladesh that gave ODI debuts to four players - Abul Hasan, Gazi, Anamul Haque and Mominul Haque.
Chris Gayle made a good start before getting out at 35 runs, when he was trying to hit Gazi out of the park.
Chasing a target of 200 runs Tamim Iqbal and Anamul Haque gave a good start to Bangladesh, Tamim made 58 runs from 57 balls.
Naeem Islam made a not out fifty to lead Bangladesh to an easy and comprehensive victory in the first ODI.
Debutant Sohag Gazi picked up four wickets as Bangladesh defeated West Indies by seven wickets in the first ODI at Khulna.