INTRODUCTION Carcinoma of the bladder is the second most common malignancy of urological organs and is still a worldwide health problem. Urothelial (transitional cell) carcinoma is the predominant histologic type. The spectrum of bladder cancer includes non-muscle-invasive (superficial), muscle-invasive, and metastatic disease, each with its own clinical behavior, biology and prognosis. Carcinoma of the bladder is at high risk of recurrence and progression of disease. Microscopically the tumor is composed of epithelial cells and stroma. The stroma consists of fibroblasts/myofibroblasts, fat, immune, vascular and smooth muscle, cells along with the extracellular matrix (ECM) and extracellular molecules. While none of these cells are themselves malignant, due to their environment, their interactions with each other, and directly or indirectly with the cancer cells, they acquire an abnormal phenotype and altered function. Extracellular matrix molecules in the urinary carcinoma of the bladder seem to play an important role in the development of invasion, progression and metastasis. Galectin-3 and fibronectin are ECM proteins that play an important role in cell adhesion. AIM The aim of this research was to analyse immunohistochemical expression of fibronectin and galectin-3 in epithelial and stromal cells of urothelial bladder carcinoma and correlate it with TNM stage, tumor grade and clinical parameters (age, sex, recurrence rate). PATIENTS AND MATERIALS Archived material from transurethral resection, cystectomy and lymphadenectomy was used in this research. Specimens carcinomas were analysed from 110 patients and divided into four groups; Ta/T1 low grade, Ta/T1 high grade, T2N0 stage and T2N1/2. Specimens where fixed in 10% buffered formalin, cut at 5μm thickness and routinely stained with hematoxylin and eosin method for diagnosis and TNM and grade classification. Additional immunohistochemistry was performed by monoclonal antibodies to fibronectin (Novocastra Laboratories 1:400) and galectin-3 (Novocastra Laboratories 1:100). The intensity of Šoip Šoipi, Disertacija immunostaining was graded semiquantitative on a scale of 0-3 and expressed as 0 = 0%; 1 = up to 33%; 2 = more than 33% to 66%; and 3 = more than 66% of positive epithelial and stromal cells. RESULTS There was statistically significant positive correlation in expression of fibronectin in epithelial tumor cells with T (p=0.001) and N tumor stage (p=0.037) as well as negative correlation in expression of fibronectin in stromal component with T tumor stage (p=0.001). There was statistically significant positive correlation in expression of galectin-3 in epithelial tumor cells compared with T tumor stage (p=0.046) connected with the more aggressive tumor biology and positive correlation in expression of galectin-3 in tumor with metastases in lymph nodes with disease relapse rate (p=0.00). CONCLUSION Increased fibronectin expression in epithelial tumor cells and decreased fibronectin in stromal tumor component was related to more aggressive tumor biology, higher tumor grade and more infiltrative tumor growth with metastatic spread to lymph nodes. These observations suggest a role for fibronectin and galectin-3 as biomarkers for bladder cancer diagnostics, staging, outcome and prognosis. In clinical practice these molecular markers could be used in creating subgroups of patients that would benefit from more frequent follow up or additional therapeutic approaches.