BACKGROUND Pharmaceutical industrial wastewater represents a challenge for biological treatment due to its complex composition. This research investigates the bioaugmentation effect of indigenous bacterial strains on the kinetics of the activated sludge process in the treatment of real high-strength pharmaceutical industrial wastewater. RESULTS Two bacterial strains were isolated from pharmaceutical effluent and identified as Aeromonas hydrophila and Pseudomonas putida. The highest removal efficiency of dissolved organic matter from pharmaceutical wastewater was 71.43% within 24 h, obtained by bioaugmented activated sludge with P. putida, at the initial concentration of activated sludge 4.39 +/- 0.37 g L-1. The biokinetic parameters of the biodegradation process were calculated using the Endo-Haldane model, where bioaugmented activated sludge showed higher affinity to pharmaceutical wastewater. CONCLUSION The biodegradation process of high-strength pharmaceutical wastewater showed enhancement through bioaugmentation of activated sludge with indigenous bacterial isolates. Considering the increasingly demand for pharmaceuticals on a global scale, the bioaugmentation potential of A. hydrophila and P. putida could contribute to enhancement of biodegradation through reduction in process time and environmental impact. (c) 2019 Society of Chemical Industry