The 51-year-old was appointed Baggies boss back in June with the aim of getting the club back into English football’s top tier within two seasons.
But it has taken Bilic just one with a 2-2 draw against QPR last night ensuring his side finished as runners up in the Championship.
A proud countryman, Bilic enjoyed huge success while in charge of his country between 2006 and 2012 and guided Croatia into the quarter-finals of Euro 2008.
But he admitted winning promotion with Albion was a landmark moment in his career.
“It is right at the top,” Bilic said when asked where getting the Baggies promoted ranks in his career.
“You don't know how exhausting it was this season. You can't imagine how proud and happy I am.
"I managed my country for six years and I said no matter which club I manage nothing will compare when you are the manager of your national team.
“I can't say it's the same but I feel as proud as I felt then.”
Albion endured a topsy turvy night at The Hawthorns with QPR opening the scoring through Ryan Manning.
Goals from Grady Diangana and Callum Robinson put the Baggies on the brink of the Premier League.
But a spectacular Eberechi Eze strike pulled the visitors level to ensure Albion fans all over the world were left biting their fingernails.
In their end, though, Bilic’s team got over the line to secure a return to the Premier League after two years away.
“I am happy, proud and tried - but I’m not feeling that now,” Bilic said.
“I don’t want to talk about the season, that’s for another time.
“But I am very proud of how we played against QPR, considering the situation.
“We were up for it. We showed character, we showed quality. Up until they scored their equaliser we were fantastic.
“We were creating chances, winning second balls, we were defending well, we were top.”
With the Brentford game at 1-1, Bilic threw Kyle Bartley forward for the final 15 minutes before then dragging him back when he was told Barnsley were leading the game 2-1.
“I told the players this morning when I was at the training ground what we were going to do in the last 15 minutes if we didn’t like the score,” Bilic added.
“Then the guys told me it was 1-1. Should we did it (put Bartley up front), because it was 1-1.
“We couldn’t rely on Brentford not scoring and we looked like we were going to score.
“We were creating and it didn’t look like they were hurting us.
“Then when Barnsley scored and it was 2-1, then I decided for Bartley to go back and let's get the result, let’s keep the ball!”