The 19-year-old joined Chelsea from Anderlecht last summer after being persistently linked with Europe's top sides over several seasons. However, the Belgian international failed to break through into the Chelsea lineup, leaving him looking for first-team opportunities elsewhere.
Lukaku spoke of how former Chelsea assistant manager and current West Brom boss Steve Clarke showed a real desire to bring him to the Hawthorns.
He told the club's official website: "Since the first day I spoke to Chelsea about going out on loan, I’ve spoken to the gaffer here a lot.
“He [Clarke] was the first person who contacted me and that means a lot.
“He’s been speaking to me every week since – even when I was in America with Chelsea – asking me about my situation.
“When you have a gaffer like that who has a desire to bring you to his club, as a young man, you feel confident to make the step into the unknown, because I don’t know the Birmingham area that well.
“But I believe that will be good for my development as a young man and I’m very happy to be here."
That, combined with advice from Chelsea manager Di Matteo and his assistant Newton, both formerly at West Brom, made the striker's mind up for him.
“I heard lots of positives about the club from Roberto Di Matteo and Eddie Newton," he added.
“They really convinced me to come here. Frank Lampard and John Terry also spoke highly about the gaffer.
“When you get that advice as a young player, you listen, and hopefully this is a good step for my career.”