The study aimed to explore the influence of Serratia marcescens, Bacillus pumilus, Bacillus siamensis and Brevundimonas diminuta on Colletotrichum acutatum, the causal agent of anthracnose in pepper, under in vitro and greenhouse conditions. Under in vitro conditions, B. pumilus and B. diminuta were the most effective PGPRs in reducing C. acutatum mycelial growth with reduction of 62.59 and 58.52 %, respectively. Soil drenching and foliar spraying application under greenhouse experiment was conducted to evaluate the effects of B. pumilus and B. siamensis rhizobacteria either as individual or combined treatment against anthracnose in pepper plant. Combined treatment of B. pumilus and B. siamensis promoted and stimulated the growth parametars of the seedlings of pepper as well as elevated the levels of non- enzymatic compounds (Free phenolic compounds and Total protein) and enzymes activity (Polyphenol-oxidase, Peroxidase and Superoxide dismutase) . Also, combined treatment caused a significant decrease in disease severity and showed potential as plant growth-promoting bacteria.