The 28-year-old midfielder joined the Baggies from Marseille on a season-long deal on transfer deadline day.
The arrangement also includes a clause that would allow the West Midlands outfit to buy the France international outright at the end of the season.
"I am happy to come to England and I am also happy to begin a new challenge," Amalfitano told West Brom's club website.
"West Brom is a very good team that plays good football - which is very important for me. I think the team has the same football philosophy as me."
Amalfitano made over 80 appearances for Marseille in his two years with the club following his move from Lorient in 2011, winning his one international cap in the following year.