The aim was to identify baseline clinical and radiological/procedural predictors and 24-h radiological predictors for clinical and functional outcomes in stroke patients obtaining complete recanalization in one pass of mechanical thrombectomy (MT) in an optimal baseline and procedural setting. A retrospective analysis was conducted of prospectively collected data from 924 stroke patients with anterior large vessel occlusion, Alberta Stroke Program Early Computed Tomography (ASPECT) score ≥6 and pre-stroke modified Rankin Scale score 0, who started MT ≤6 h from symptom onset and obtained first-pass complete recanalization. A first logistic regression model was performed to identify baseline clinical predictors and a second model to identify baseline radiological/procedural predictors. A third model including baseline clinical and radiological/procedural predictors was performed, and a fourth model including independent baseline predictors from the third model plus 24-h radiological variables (hemorrhagic transformation [HT] and cerebral edema [CED]). In the fourth model, higher National Institutes of Health Stroke Scale (NIHSS) score (odds ratio [OR] 1.089) and higher ASPECT score (OR 1.292) were predictors of early neurological improvement (ENI) (NIHSS score ≤4 points from baseline or NIHSS score of 0 at 24 h), whereas older age (OR 0.973), longer procedure time (OR 0.990), HT (OR 0.272) and CED (OR 0.569) were inversely associated with ENI. Older age (OR 0.970), diabetes mellitus (OR 0.456), higher NIHSS score (OR 0.886), general anesthesia (OR 0.454), longer onset-to-groin time (OR 0.996), HT (OR 0.340) and CED (OR 0.361) were inversely associated with 3-month excellent functional outcome (mRS score 0-1), whereas higher ASPECT score (OR 1.294) was a predictor of excellent outcome. Higher NIHSS score was a predictor of ENI but inversely associated with 3-month excellent outcome. Older age, HT and CED were inversely associated with both good outcomes.