Untreated waste materials discharged from the pharmaceutical industries due to lack of legislative regulations may cast the unfavorable consequences within the environment. The present study endeavored to stress the proliferation of harmful microorganisms in both treated and untreated pharmaceutical wastes along with the assessment of the drug resistance patterns of the isolates. The existence of the total viable bacteria and fungi was estimated up to 109 and 106 colony forming unit (cfu)/mL, respectively, in treated pharmaceutical wastes. For the untreated wastes, the bacterial and the fungal load were 106 and 103 cfu/mL, respectively. Both categories of samples were found to be contaminated with an array of pathogenic bacteria including Klebsiella spp., Vibrio spp., Bacillus spp., and Staphylococcus spp. Interestingly, an elevated range of pathogenic contamination was noticed in the treated samples up to 105 cfu/mL while a comparatively reduced microbial load was observed in the untreated samples within a range of 102–104 cfu/mL. Most of the isolates exhibited resistance against commonly used antibiotics while several isolates showed multi‐drug resistance. Conversely, almost all untreated samples were found to exhibit in vitro anti‐bacterial activity against eight categories of laboratory isolates tested.