Medicinal drugs of low-quality likely due to microbial contamination can result in increased morbidity and mortality thereby reducing the human population and may also result in emergence of resistant strain organisms in the environment. Studies suggest that there are a lot of counterfeit and substandard anti-tuberculosis drugs in circulation especially in Africa that are used for the treatment and control of tuberculosis whose damage on public health were mostly underestimated. Research on microbiological quality of anti-TB drugs is regrettably inadequate and scarce with most of the researches focused only on determining the active pharmaceutical ingredients of the drugs. This research aimed at assessing the microbiological quality of the anti-TB drugs used at DOTS Centres and Pharmacies within Kaduna metropolis, specifically to determine the total aerobic microbial count, total combined yeast and mould counts, the presence of indicator organisms; Escherichia coli, Salmonella species, Staphylococcus aureus and Pseudomonas aeruginosa as well as the susceptibility of the isolates to standard antibiotics. A stratified random sampling was used. A total of fifty-two (52) samples comprising of Rifampicin, Pyrazinamide, Isoniazid, Ethambutol and 4FDC were collected for the study. Methods specified in the United States Pharmacopoeia (USP, 2019) under the test for specified organisms and enumeration test were adopted for this research work. The study conducted established that the anti-TB drugs used at DOTS centres and Pharmacies within Kaduna metropolis, Kaduna, Nigeria do not contain any of the indicator organisms but some of the selected anti-TB drugs are contaminated with other strains of microorganisms with some not meeting the requirement for total aerobic microbial count and total yeast and mould count. The microbial contaminants found include species of; Bacillus, Klebsiella, Enterobacter, Penicillium, Fusarium, Alterneria, Curvularia, Aspergillus, Candida and Sporotricum. Some of the selected isolates obtained from the selected anti-TB drugs were not susceptible to the standard antibiotics used; Augmentin, Chloramphenicol, Ciprofloxacin, Gentamicin, Amoxicillin and Ofloxacin, with highest resistance recorded in Amoxicillin for all the bacterial isolates. However, all the Candida species were susceptible to the antifungal drugs; Ketoconazole, Fluconazole, Clotrimazole and Itraconazole