The Hammers signed Joe Hart, Pablo Zabaleta, Marko Arnautovic and Javier Hernandez over the summer.
But all the talk since has focused on the players he didn't get whether by choice or not.
The manager has admitted William Carvalho and Andre Gomes were all but done before falling through just before the deadline.
But supporters and pundits have questioned Bilic's judgement after he rejected at least three deals for players.
For much of the transfer window the Nigerian looked on the verge of a move to East London.
That was until Bilic made the bold call to pull the plug on the deal at the 11th hour, as reported by the Evening Standard.
Then after the window closed Hammers co-owner David Sullivan publicly stated on the club's official website that his manager had turned down the chance to sign Bayern Munich's Renato Sanches and Paris Saint Germain midfielder Grzegorz Krychowiak.
Many saw Sullivan's decision to reveal that information as somewhat suspicious, but some felt Bilic has made a huge mistake.
However after a first win of the season, 2-0 over Huddersfield on Monday night, is Bilic being vindicated?
Sanches made what was one of the worst debuts in recent Premier League history as he surrendered possession a record 23 times in the defeat to Newcastle last time out.
Pundit Jamie Redknapp had backed Sanches to be the star signing of the summer but after a shocking debut the former Liverpool midfielder admitted his 'confidence looks shattered'.
Meanwhile West Brom were soundly beaten 3-1 by newly promoted Brighton with Krychowiak failing to impress.
His manager Tony Pulis feels the Poland international will improve after admitting he wasn't at his best.
“With Gregor, that’s his first game for a long time,” Pulis told The Birmingham Mail.
“He’ll get better. I thought he done alright, but he’ll get better with game time.”