The scope of this study was to evaluate the prevalence of comorbidity in elderly subjects with neoplastic diseases, and to compare it to those without tumor pathologies. Three groups of patients have been considered: (A)35 elderly oncological patients; (B)38 young/adult oncological patients; (C)25 elderly patients without oncological pathology. After clinical evaluation and pathohistological diagnostic analysis, the concomitant pathologies have been estimated by means of two methods: (i)the Satariano's score; and (ii)the Charlson Comorbidity Index (CCI). Statistical analyses performed by using the Chi-square and the Student's t-test gave coherent results, and revealed that the prevalence of comorbidities was the highest in Group C, and displayed significantly reduced prevalences in the sequence Group B, Group A.