Testicular cancers are tumours of the young adult (15 - 35 years), and it is a rather rare pathology in African black. However, the risk of developing these cancers becomes higher if the testicle does not descend. In our context, these undescended testicles often go unnoticed, which poses the problem of surveillance. We report a case in a patient of 24 years who consulted for pain plus hypogastric mass, in whom at the end of the clinical, paraclinical and surgical investigations we retained the diagnosis of seminoma of the right testicle. This is the first case in our daily practice. Conclusion: The rarity of tumours on the undescended testicle should not cause their diagnosis to be misunderstood because of the seriousness of cases diagnosed late.