Lacazette - a summer signing from Lyon - has already netted four goals in eight appearances for the Gunners, and Ramsey has backed the Frenchman to continue to make an impact in North London.
The 26-year-old told the club's official website: "I think he's made a great start. He's very technically good, he's very clean with his touches and his link-up play and he's a great finisher.
"We've seen some fantastic finishes so far from him and I'm sure there will be many, many more to come as well, so it's exciting times for him personally and for us to have him here."
Earlier this week, Lacazette revealed that he rejected interest from Paris Saint-Germain before opting to sign for Arsenal.