Wisdom check or not

[Hunterx]

Is stunning fist a wisdom check or not ?

[GrayDeath]

No, Stunning Fist is a special Attack the Monk gets.

Now if you wanted to ask if it REQUIRES a Wisdom Check: Also no.
But the Target must pass a save (see SRD for the Detaisl).

[Vaern]

An ability check is a generic roll that uses an ability score modifier to determine the outcome of an action that doesn't fall into the description of any particular skill. Essentially, it's an untrained skill check. Wisdom generally involves perception - the Rules Compendium lists "Recognizing a stranger you've seen before" as an example of an action that would involve a Wisdom-based check, but does not fall under common Wisdom-based skills such as Spot or Sense Motive.

Stunning Fist is just an effect that is applied to a normal attack. The attacker declares that he is using Stunning Fist, and if the attack deals damage then the target is affected by the feat. The action is an attack roll, not an ability check, and doesn't use your wisdom modifier to determine whether it hits or takes effect.

The DC of the saving throw against Stunning Fist is based on the attacker's Wisdom. The saving throw DC is a set number and doesn't involve any rolling of a die. It is modified by Wisdom, but is not a check of any sort.

The target defends against the Stunning Fist with a Fortitude saving throw, which is modified by his own Constitution.

There are no Wisdom checks involved at any point in the process of hitting someone with Stunning Fist.