Background: Bladder urothelial carcinoma (BUC) shows varying histological features, behavior, and prognosis. The two most common genes altered in BUC were TP53 and FGFR3. The FGFR3 alteration related to lesser aggressiveness than TP53 and anti-FGFR3 targeted therapy is being investigated. This study determined p53 and FGFR3 expression in BUC cases treated at Prof. dr. IGNG Ngoerah Hospital. Methods: A cross-sectional observational analytic study was conducted in 2023 in the Anatomical Pathology Laboratory at Prof. dr. IGNG Ngoerah Hospital. The subjects were forty-three BUC patients from 2018-2022 who met the eligibility criteria obtained by consecutive sampling. Tumor aggressiveness, represented by the degree of differentiation and depth of invasion, was assessed from HE slides, resulting in low and high-grade muscle-invasive (MI) and non-muscle-invasive (NMI) cases. The p53 and FGFR3 expression were assessed with immunostaining and categorized as low and high expression with 50% and 70% cut-off of positive cells, respectively. The association between variables was statistically analyzed with the Fisher Exact test. Results: Most patients were male (82.44%), aged >50 years (92.37%), invasive type (62.60%), high grade (80.12%), and MI (52.67%). Immunostaining showed a predominance of high p53 expression (60.5%) and low FGFR3 expression (62.8%). Some cases showed concomitant p53 and FGFR3 expression. Statistical analysis revealed no association between p53 expression and the degree of differentiation and depth of invasion (p=0.625; 0.388, respectively). There was a significant association between FGFR3 expression and the degree of differentiation (p=0.003) but not with the depth of invasion (p=0.110). Conclusion: In conclusion, p53 expression was not associated with BUC aggressiveness, whereas FGFR3 expression was significantly associated with the degree of differentiation but not with the depth of invasion. Concomitant p53 and FGFR3 expression may reflect the complexity of BUC carcinogenesis. Further studies are needed for a better understanding of TP53 and FGFR3's involvement in BUC carcinogenesis and therapy.