The sides meet at San Siro as Inter look to bolster their hopes of securing European football, but Stefano Colantuono's men have taken maximum points from their last three outings.
With Mazzarri's Inter looking to make it seven league games unbeaten, the former Napoli boss is not taking the task lightly.
"Atalanta play good football, they have some quality players and they're also free of any pressure because they've already ensured their top-flight status," he said.
"They're tough opponents and this is a game we must approach very carefully. Atalanta are a bogey team for lots of sides. We have to perform to the best of our ability because they'll be giving it a good go."
Inter have won their last two and are yet to concede this month, but Mazzarri remains well aware of the threat Atalanta will pose - after their comprehensive 3-0 win over Sampdoria last time out.
"There are no easy games in Italy. You have to respect all the teams and approach every match with the same level of concentration," he added.
"We must focus first and foremost on ourselves because we've seen that when we're on the top of our game we can make life difficult for anyone.
"We must not think about anything else right now. We'll see where we are come the end of the season."
