Back ground: Cystoscopic examination and histological evaluation of bladder tissues are considered the gold standard for initial diagnosis of bladder cancer. For decades, researchers explore novel, non-invasive, specific and sensitive biomarkers for preliminary diagnosis and surveillance of bladder carcinoma. Exosomes are nano-sized vesicles present in various biological fluids and encapsulate huge number of biomarkers such as proteins, mRNAs and miRNAs. Caveolin-1(Cav-1) is a major protein of caveolae structure that expressed in a variety of cells and has a fundamental regulatory role in cancer development. Therefore, determination ofexosomal Cav-1 expression in different stages of bladder cancer is a critical concern for clinical diagnosis and prognosis. Methods: Exosomes Cav-1 was isolated and extracted from urine and serum samples of 79 patients of bladder cancer at different stages (T0:T3) and 12 healthy controls.Exosomal Cav-1 expression levels were determined by using Rt-qPCR technique. Results:Exosomal Cav-1expression levels at different stagesof bladder cancer patients were significant in both urine and serum samples. The current study showed upregulation ofCav-1 amongserum (4.03, 9.20, 14.25, 26.92folds) and urine samples (2.55, 3.64, 8.33, 19.37folds) comparative to tumor invasiveness (T0-T3).Serum Cav-1 is more sensitive (96.2%) than that in urine (86.1%) although urine Cav-1 is more specific(94.3%). Conclusion: Exosomal Cav-1 expression could be used as a crucialnon-invasive biomarker in diagnosis and prognosis of bladder cancer in serum and urine.