The uncontrolled and unrestricted use of antimicrobials may lead to the accumulation of undesirable drug residues in the treated animals and their products. In the poultry industry of many developing countries such as Kenya there is lack of affordable, easy to perform antibiotic residues screening methods. The aim of this study was to evaluate the performance of Bacillus cereus and Bacillus subtilis as test organisms for assay of tetracycline and beta-lactam antibiotics in chicken meat. Microbiological detection was achieved by agar well diffusion. Results showed that oxytetracycline (OTC) and penicillin G (PEN G) were reliably detected below the maximum residue limits (MRLs), of 50ng/g in both liver and kidney for PEN G and 600ng/g in liver and 1200ng/g in kidney for OTC, by the two bacterial species. B. cereus and B. subtilis can therefore be used effectively for routine screening for residues of PEN G and OTC in chicken kidney and liver tissues. The screening test is technically simple and can be carried out in most laboratories in both the developed and developing countries.