A cross-sectional study was conducted on ruminants (cattle, sheep and goats) slaughtered at Haramaya University and Haramaya municipal abattoirs from November 2013 to April 2014 in Haramaya, eastern Ethiopia. The objective of the study was to identify types and estimate the prevalence of foreign bodies in the rumen and reticulum of domestic ruminants in the area. From 810 randomly selected study animals, 422 (52.1%) were found to have foreign bodies. Of the 332 cattle, 193 sheep and 285 goats examined, 144 (43.4%), 109 (56.5%) and 169 (59.3%) respectively were found with various types of foreign bodies. The prevalence of foreign bodies was significantly (?2 = 17.53, p < 0.05) higher in sheep (59.3%) and goats (56.7%) than in cattle (43.4%). Overall the prevalence of foreign bodies in study animals with poor body condition was significantly higher (?2 = 38.57,p < 0.05) than in those with medium and good body condition. A higher percentage of foreign bodies occurred in the rumen alone (87.9%) than in the reticulum alone (5.0%), with the rest present in both. Significantly higher proportions of foreign bodies were observed in the rumen of cattle (?2 = 332, p < 0.05), sheep (?2 = 193, p < 0.05) and goats (?2 = 285.0, p = 0.000) than in the reticulum. Plastic was the most commonly encountered (79.2%) foreign body, followed by cloth (15.3%) and rope (12.3%). In addition, metal (0.9%) and calcified material and/or stone (1.0%) were found in the reticulum of cattle. Lack of a plastic waste disposal system in the area as well as communal/free grazing of livestock in highly waste-polluted areas seemed to be major factors in the high occurrence of foreign bodies in ruminants. To change this, collaborative intervention schemes involving professionals, policy makers, livestock keepers and environmental activists are needed