There is a growing evidence that obesity is not only a weight problem, but it is linked to adverse neurocognitive outcomes. Besides obesity, frontal lobe based cognitive deficits in depressed patients are confirmed, and interactions between depression and obesity are known. In our study we investigated the relationship between cognitive functioning, mood and female obesity. Our findings revealed reduced mental flexibility and sustained attention capacity in obesity together with the presence of depressive mood. The mediating role of depression is confirmed. Positive emotion was associated with cognitive functions independently from BMI. Positive affectivity in obesity treatment is discussed.