Hydatid disease constitutes a genuine public health problem. Hydatidosis varies from one region to another, and its prevalence in the Maghreb is moderate. We report the case of a 43 year old male who presented with a painless right testicular mass of one year duration. Local examination showed hard, nontender, right testicular mass of 9x5 cm. Levels of serum a-fetoprotein and human chorionic gonadotrophin were within normal limits. Scrotal ultrasound revealed heterogenous mass arising from the testicle. High inguinal orchidectomy was performed as diagnosis was not absolutely clear. The final pathology report revealed hydatid cyst of the testis. In most cases, ultrasound is the key of diagnosis but sometimes imaging is not specific and only histological examination allows confirming the diagnosis as in the case of our patient.