The common scab disease caused by Streptomyces scabiei is an important disease infecting potato (Solanum tuberosum). In this study, twelve S. scabiei isolates were obtained from different governorates in Egypt. Efficacyof treatments with certain bioagents (Pseudomonas fluorescence, Bacillus subtilis, Trichoderma harzianum, Trichoderma viride) and chemicals (Capitan, Spectropan) to control common scab disease was evaluated. The results showed that treatment with Spectropan in infection time at a concentration of 2 mg/mL exhibited the highest disease reduction percentage, 61.13 and 65.49%, followed by Trichoderma viride by52.63 and 69.8% for 2018 and 2019 seasons, respectively. Treatment of potato) Lady Rosetta cultivar) with Pseudomonas fluorescence and Bacillus subtilis resulted in a significant increase in the total phenols content and peroxidase and polyphenoloxidase activities during inoculation time and after inoculation time of Lady Rosetta cultivar with S. scabiei. However, the lowest activities of peroxidase and polyphenoloxidase were recorded due to treatment with Spectropan in inoculation time or after inoculation time. The obtained results revealed that the application of certain bioagents is an efficient method to control common scab in potatoes.