Since long-term cancer survivorship is a reality for an increasing number of people, understanding their cognitive functioning is useful for both research and clinical purposes. This study described the cognitive functioning of Italian long-term cancer survivors, using both an objective standardized battery and a self-report questionnaire. A total of 136 Italian adults 5+ years free from cancer and its treatments were administered the Esame Neuropsicologico Breve, the Self-Assessment Scale of Cognitive Functioning, and assessments of other psychological dimensions. A total amount of 15% of the sample showed impaired performance on 2+ of the assessed cognitive functions, and 32% had 1+ impaired function. The subjective perception of their cognitive functioning was worse in the present sample, compared to the normative data (p < 0.001). Cognitive functioning, objectively and subjectively measured were significantly correlated (p = 0.006). The number of tests scored outside the normal range correlated positively with depression (p = 0.042) and negatively with both the estimated total IQ (p < 0.001) and with estimated performance IQ (p = 0.001). Self-perceived cognitive functioning correlated positively (p < 0.001) with depression, anxiety, and fatigue. These data document how cognitive difficulties may remain for a long time in cancer patients, who are likely to continue to subjectively perceive themselves as impaired, although sometimes to a greater extent than objective impairment.