The Frenchman made a bright start to his tenure at the Hawthorns, winning four of his first five league games but performances have tailed off ever since.
The West Brom fans grew discontent with Ismael’s brand of football and successive losses to Millwall and Preston North End have the left the Baggies in fifth place, eight points adrift the automatic promotion places.
The club announced Ismael had left his position in a statement on Wednesday afternoon, which read: "West Bromwich Albion Football Club can confirm Valerien Ismael has today left his position as head coach.
"Assistant head coach Adam Murray has also departed The Hawthorns.
"The club would like to place on record its thanks to Valerien and Adam for their efforts and wishes them well in the future.
"The process of recruiting a new head coach is now under way and an appointment will be announced in due course."
Former Newcastle United manager Steve Bruce is an early candidate to take over the club.
West Brom were relegated from the Premier League last season.
