OBJECTIVE Ulcerative colitis increases the risk of developing dysplasia and colitis-associated cancer (CAC). The purpose of this study was to determine the risk factors as well as protective measures for disease burden, need for colectomy and the development of CAC in ulcerative colitis (UC) patients. METHODS A cohort of n = 434 UC patients was evaluated. Data analysis was performed by univariate and multivariate logistic regression. Odds ratios (OR) and 95 % confidence intervals (CI) were calculated, and significance was assessed by the likelihood ratio test. RESULTS Mean patient age at UC diagnosis was 45.7 ± 15.1 years which manifested mainly as pancolitis (47 %) or left-sided colitis (45.2 %). CAC was detected in ten patients (2.3 %). UC disease duration was strongly associated with the risk of CAC (P < 0.0014); disease duration between 9 and 15 years: OR of 2.5 (95 % CI 0.2-41.1), more than 15 years: OR of 21.4 (95 % CI 2.6-173.6). The risk of developing dysplasia (low-grade intraepithelial neoplasia, LGIEN and high-grade intraepithelial neoplasia, HGIEN) or the need to undergo colectomy was also significantly related to disease duration (P = 0.006, P = 0.002, respectively). Established anti-inflammatory medication (e.g., 5-ASA, anti-TNF-α) significantly reduced the risk of both dysplasia and CAC (P = 0.02). CONCLUSIONS Despite the use of modern therapies for UC, CAC rates remain high. In our study, risk factors included disease duration while anti-inflammatory therapies reduced the risk. Effective control of the intestinal inflammation also reduced the disease burden as indicated by decreased risk of requiring colectomy, underscoring the need for sufficient surveillance and anti-inflammatory therapies.