[Distribution of ovine hydatidosis in Sardinia, 1987-1988]. 
The prevalence of Echinococcus granulosus in sheep was examined in Sardinia between June and September 1987-1988.  Of the examined sheep 243 were being pastured in fenced fields while 1084 were being pastured in open fields.  An infection rate of 1.6% was recorded in the first group of sheep, and 86.7% in the second.  The prevalence rate differed in various parts of the region, ranging from 79.4% (Oristano province) to 95% (Nuoro province).  Of the parasitized sheep 7.9% harboured only fertile cysts, and 74.1% only sterile cysts.  The latest figure is surprising compared to data previously reported in the literature.  Most of the sheep examined were infected in both organs (67.4%) but only 27.4% of these showed a massive infection with over 10 hydatid cysts.  The variation in prevalence rate and epidemiological implications are discussed.