Approximately 19.3 million people were diagnosed with cancer and about 10 million people died of cancer in 2020. The evaluations of the International Agency for Research on Cancer on carcinogenic risks have identified several carcinogens so far, but the etiology of cancer is still not sufficiently elucidated. The nutritional composition of ultra-processed food and worldwide increase in its consumption have prompted research into its impact on health. The aim of this study was to assess the risk of colorectal, breast and prostate cancer associated with high consumption of ultra-processed food. A comprehensive literature search of PubMed database was performed, using the keywords “ultra-processed food” and “cancer”. Abstracts and full-texts were screened for inclusion and there were no language restrictions. Studies conducted in humans and designed as case-control or cohort studies were included. Exclusion criteria were studies not done in humans, reviews, case-reports. Exposure of interest was high level of consumption of ultra-processed food. Outcome of interest was occurrence of cancer (colorectal, breast, prostate). We extracted estimates from models which were adjusted for most variables. Meta-analyses were performed using the generic inverse variance method, producing a pooled Hazard Ratio (HR) with 95% Confidence Interval (95%CI). All analyses were done in Review Manager, version 5.4.1. High consumption of ultra-processed food was significantly associated with the risk of colorectal cancer (HR=1.26, 95%CI 1.14-1.39, p < 0.00001). The risk for breast cancer was increased but not significantly (HR=1.14, 95%CI 0.99-1.32, p=0.08) in persons consuming ultra-processed food, while the risk was not increased for prostate cancer (HR=0.98, 95%CI 0.84-1.15, p=0.82). The results of this meta-analysis show that the risk of colorectal cancer is significantly increased in persons with high consumption of ultra-processed food. To the best of our knowledge this is the first meta-analysis which investigated the risk for colorectal, breast and prostate cancer and high level of consumption of ultra-processed food. However, the limitation of the present analysis is the small number of included studies identified using only one database, mainly due to the novelty of the research question, still no heterogeneity was detected. Further research is necessary in order to evaluate the role of ultra-processed food in the occurrence of cancer.