Despite the growing of contamination of foods of animal origin with chemicals during production, processing and storage, less attention being paid for the potentially present chemical residues in such foods (meat, milk, eggs and their products). This study was carried out to assess the chemicals and veterinary drugs used, and their possible occurrence as residue in dairy and poultry products in randomly selected dairy and poultry farms, and milk and animal feed processing plants located in Bishoftu and Modjo, central Ethiopia through questionnaire and observation. The result of this study showed that antibiotics, mainly penicillin-streptomycin and ampicillin-cloxacilin combination were used in all dairy farms while oxytetracycline and sulfa drugs were used by 85.7% and 57.1% of dairy farms. Oxytetracycline, amoxicillin, ciprofloxacillin, and sulfa drugs were used in 100%, 71.4%, 28.6%, and 28.6% of poultry farms, respectively. The study also revealed albendazole and ivermectin were commonly used in 96.4% and 71.4% of the dairy farms, respectively while piperazine was a common anthelmintic used in 31.0% of poultry farms. The antiprotozoal drugs commonly used in poultry farm were amprolium (100%) and sulfa drugs (26.3%) while the commonly used drug in dairy farms was sulfa drugs (50.0%). Antiseptics, namely, savlon (82.2%), iodine tincture (53.3%) and denatured alcohol (53.3%) were commonly used in dairy farm whereas disinfectants, such as, hydrogen peroxide (83.3%), sodium hydroxide (66.7%), and formalin (19.0%) were commonly used in poultry farms though small number of dairy farms also used formalin (17.8%) and hydrogen peroxide (10.7%). Among the rodenticides used in farms, zinc phosphide was used more in poultry farms (33.3%) than dairy farms (14.3%). Different chemicals were also used in the milk and feed processing plants. We conclude that there are high possibility of drug and chemical residues occurrence in poultry and dairy products in the area.