A cross-sectional epidemiological study was conducted from November 2006 to October 2007 to determine the epidemiology of bovine hydatidosis in cattle slaughtered at Mekelle Municipal abattoir in Tigray Region of Ethiopia. A one-year long ante and post mortem examination of 4481 cattle slaughtered at the abattoir showed a prevalence of 32.1% (1,439) for hydatidosis. The percentage of hydatid cysts in different internal organs was observed as 25.62% in the lung, 12.56% in the liver, 0.47% in the heart, 0.17% in the kidney and 0.42% in the spleen, respectively. In this study, the lung was found to be the most predominantly affected organ (63.0%) followed by the liver (36.4%). As regards size of the cyst, the small sized cysts had the highest percentage (80.39%), followed by medium sized cysts (10.90%) and large sized cysts (8.69%). The monthly prevalence of hydatidosis was highest (36.44%) in July and lowest (25.11%) in April indicating that different seasons significantly affect its prevalence (chi(2) = 30.3013, d.f. = 11, and p = 0.003). Age, sex, breed and origin of animal didn't have significant effect (p > 0.05) on prevalence of the disease; however, body condition score had statistically significant effect on the disease prevalence (chi(2) = 17.8481, d.f. = 2, p < 0.001). Of the 7,315 cysts examined for fertility and viability, 2349 (32.11%) were sterile, 3979 (54.39%) calcified, 782 (10.66%) fertile and viable while 205 (2.80%) were fertile but nonviable. It was observed that hepatic and pulmonary cysts had fertility rate of 11.75% and 13.83%, respectively. Out of the total cysts examined, the proportion of viable protoscoleces was 10.69%. The present study provides baseline data on the current status of the disease in the area.