The authors present an observation of intraorbital hydatid cyst. They review the literature and discuss the main data of such a rare lesion. Hydatid cyst should be systematically evoked in any case of tumoral exophthalmia developed in a young patient, particularly if he comes from an endemic country. The pre-operative diagnosis relies on the confrontation between clinical and echographical data, and C.T.-scan imaging. The only treatment is surgery. A puncture performed at the beginning of the surgical procedure will confirm the diagnosis. In fact, it should be indicated for every intra-orbital neoplasm observed in a country of endemicity, mostly when the preoperative diagnosis is difficult, that is when no C.T.-scan or echography are at disposal. The infectious prognosis is excellent; but the functional one depends on the precocity of surgery and remains reserved in most cases.