This study was aimed at evaluating the efficiency of the oxidation ponds in industrial (Tannery) wastewater treatment. The analyses were carried out on selected tanneries of Modjo area, East Shewa, Oromia National regional State, Ethiopia and Mesaco Global Tanneries. In order to evaluate the efficiency of oxidation ponds in treating industrial wastewater, a total of 27 samples from three sampling sites of the oxidation ponds of each tannery were collected and analyzed for the major physico-chemical and biological parameters; E.C, pH, BOD, COD, Cr+3 , S-2, N-NH3, N-NO3, TKN, PO4, TSS, TS, TDS, SO4, Cl-, Mg+2, Ca+2, TC and FC. The result of analyses revealed that MOP had the most BOD, TC and FC removal with the value of 67.7%, 92% and 93% respectively to that of Chrome oxidation pond with BOD, TC and FC percentage removal of 52.5, 75.4 and 81.5 respectively, and sulfide oxidation pond having BOD, TC and FC percentage removal of 64, 72.6 and 86.2 respectively. Similarly, the study showed that the highest percentage removal of TSS and S-2 were achieved in Sulfide oxidation pond with value of 93% and 89.8% respectively, and 65.7% of Chromium (Cr+3) removal was achieved in Chrome oxidation pond. However, the COD removal efficiency of the oxidation ponds; Chrome oxidation pond, Sulfide oxidation pond and Mesaco global oxidation pond was 35%, 44.8% and 37% respectively. In addition, the study findings revealed that the concentrations of N-NH3 and TKN have shown increasing trends in sulfide oxidation pond, while the concentration of N-NO3 has been declined with percentage removal of 82.5%. Though the concentrations of N-NH3 and TKN were not in increasing trends in the Chrome oxidation pond and Mesaco oxidation pond, their removal efficiencies were very low, 32.6% and 48.4% respectively in Chrome oxidation pond, and 47.2% and 54.6% respectively in Mesaco oxidation pond. It was concluded from these results that the oxidation ponds were inefficient in removing nutrients, COD, BOD and Cr+3 due to absence of multiple ponds neither connected in series nor in parallel, lack of uniformly mixing of the wastewater in the ponds, and pre screening of coarse material prior to entering the oxidation ponds. Thus, effective removals of these parameters need sequentially connected; anaerobic – facultative – maturation ponds systems with reasonable organic loading and retention time.