Yes. Each monster has two actions, but only one of them may be an attack or an "attack-like ability". They can move twice, or open a door and move, or open a door and make a scenario-based action, or...
Just to clarify: "attack-like ability" means a special ability that allows the monster to perform an attack. There are a few special monster abilities that cause damage or fatigue loss without actually performing an attack; these do not count for the one attack per turn rule.