<strong>Introduction:</strong><span style="font-family:Verdana;"> Deep vein thrombosis is a frequent disease, its origin is most often multifactorial. Venous thromboembolic disease (MVTE) and cancer are two frequently entangled pathologies. Here we report the diagnosis of deep vein thrombosis that discovered prostate cancer in an 88-year-old Guinean man. On clinical examination, there was a painful and hot swelling of the right leg, an absence of sloshing of the calf, a positive sign of Homans. The digital rectal examination revealed an enlarged prostate with an irregular surface. Cardiopulmonary auscultation was normal. The electrocardiogram showed a regular sinus rhythm at 65 cycles/min, with no sign of enlarged cavities or conduction disturbance. Venous Doppler ultrasound of the lower limbs showed the presence of an extensive acute deep venous thrombosis of the right sural vein extended to the popliteal and to the homolateral deep femoral. The reino-vesico-prostatic ultrasound c</span><span style="font-family:Verdana;">o</span><span style="font-family:Verdana;">ncluded in a heterogeneous prostatic hypertrophy with projection of a median lobe associated with a bladder of fight with an important post voiding residue evaluated at 170 ml</span><span style="font-family:Verdana;">;</span><span style="font-family:Verdana;">the rate of specific antigen of the prostate PSA was at 84.87 ng/ml. The pathology analysis made after a prostate biopsy puncture concluded with an adenocarcinoma with a Gleason score of 3.</span><span style="font-family:Verdana;"> </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> The association of venous thromboembolic disease (MVTE) and neoplasia is frequent. The existence of active cancer in a patient is a known risk factor for MVTE and, conversely, the discovery of a first episode of deep vein thrombosis (DVT) or pulmonary embolism (PE) may be the mode of revelation of cancer.</span>