This study was conducted to evaluate the quality of different brands of injectable oxytetracycline solutions circulating in the legal markets  of Addis Ababa with respect to physicochemical characteristics and sterility. Nine brands of oxytetracycline with thirteen different batches were randomly purchased from veterinary drug stores in the city. The physical assessment was performed by using a checklist that was  prepared based on the World Health Organization guidelines. The qualitative and quantitative analysis of active pharmaceutical ingredients (API) was performed by High-Performance Liquid Chromatography. The sterility test was assessed by using the direct  inoculation method. All samples passed the identity, the assay, and the sterility tests. However, there were statistically significant  differences (P<0.05) among brands in the quantity of API. The highest percentage of the API was recorded in brand G (112.12%± 1.86) while the lowest was seen in brand H (92.61%± 1.5). This study revealed that all brands passed both physicochemical and sterility tests except for the differences in the API level among brands. Strict regulation, monitoring, and wider-scale surveillance are required to assure sustainable control of substandard, unsterile, and falsified pharmaceutical products in the country.