Preoperative prediction of shunt surgery outcome is difficult. A test to predict outcome is missing. The use of diffusion tensor imaging (DTI) as a bioimaging marker was investigated. DTI parameters in white matter tracts were compared between patients and healthy controls, and also correlated with changes in clinical findings after shunt surgery. Significantly differences between healthy controls and patients were found. Correlations were found between preoperative DTI results and changes in clinical findings after shunt surgery, suggesting DTI to be a supportive tool for prediction of clinical outcomes from shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH).