Objective To investigate the findings in the assessment and prognosis of the elderly cancer patients with comprehensive geriatric assessment (CGA) in 7 hospitals in Sichuan Province. Methods CGA was made for 488 elderly cancer patients (lung cancer, prostate cancer, colorectal cancer and malignant lymphoma) aged 65 years or over, who were treated in 7 hospitals in Sichuan Province from July 2012 to January 2014. An analysis was made of their geriatric syndrome, and a comparison was made of the prognosis between groups with different functional levels within 1-year follow-up. SPSS statistics 22.0 was used for data analysis, and Chi-square test for comparison groups. Results Severe complications were seen in 76.4%(373/488), impaired instrumental activities of daily living (IADL) in 68.6%(335/488), visual impairment in 68.2%(333/488), high risk for falling in 51.0%(249/488), and social support deficiency in 10.0%(49/488). Age group 65-75 years had higher risk and higher proportion of malnutrition than age groups of 76-85 and of >85 years, the difference being statistically significant (P<0.001). Progression or recurrence of cancer was observed in 37.5%(183/488) during the follow-up period. The rate of progression/recurrence was 41.5%(92/222) in dysfunctional group, 16.7%(4/24) in functionally independent group, and 36.0%(87/242) in disability group, the difference being statistically significant (P<0.05). The 1-year mortality rate was 11.9%(58/488) with no death in the functionally independent group. The mortality rate in the disability group was 21.1%(51/242), which was significantly higher than that in the dysfunctional group 3.4%(7/222) (P<0.001). Of 273 patients who received chemotherapy, 76.9%(210/273) did not complete the expected course of treatment. In the disability group, 100.0%(96/96) did not complete the expected course of treatment, which was higher than 67.1%(110/164) in the dysfunctional group and 30.8%(4/13) in the functionally independent group, the difference being statistically significant (P<0.001). Side effects of radio/chemotherapy were seen in 79.9%(218/273), of which 19.0%(52/273) were Grade 3 or above. There was no statistically significant difference in the incidence of side effects between groups (P=0.108). Conclusion Geriatric syndrome is common in hospitalized elderly tumor population, in which complications and IADL are the most common, and some dysfunctional patients are prone to tumor progression/recurrence. The proportion of those who did not complete the expected course of treatment and 1-year mortality were high in the disabled patients.