The aim of this study was to examine early cognitive performance after a delirium in elderly general hospital patients. Patients were divided into a delirium (n = 47) and a control (n = 25) group. One week before discharge and after delirium had cleared in the first group, all patients completed a neuropsychological test battery (The Cambridge Cognitive Examination-Revised [CAMCOG-R]). Group differences in cognitive performance were analyzed adjusting for differences in baseline sociodemographic and clinical variables. Adjusting for group differences in baseline variables, the delirium group performed significantly worse than the control group on CAMCOG-R; its subdomains language, praxis, and executive functioning; and on Mini Mental State Examination derived from CAMCOG-R. The occurrence of delirium in hospital thus detrimentally affects early cognitive performance.