Mbappe has developed into a key figure at Monaco since breaking into the first team and has played a large role in their successful season so far, with Leonardo Jardim's side on the verge of Ligue 1 glory.
Benzema is impressed with the 18-year-old's rise to prominence but has also warned his compatriot not to get carried away.
"What Mbappe is doing in Ligue 1 and has done in the Champions League is exceptional," Benzema told L'Equipe.
"The last player who seemed as good at this level was Neymar.
"He is a phenomenon for his age, but he needs to establish himself in the long term. At the start, the superlatives come quickly. I was branded in the same way when I made my debut in Lyon's first team aged 17.
"You have to keep the same standard when you grow and are in difficult times. It is then that you see if you can make a step up, even more so if you are at a very big club or if you remain a good player as many have after shining very young."
Mbappe has netted an impressive 25 goals in 42 appearances in all competitions this season.