The reliability of test results is crucial in today's evidence-based medical care. Additionally, the ISO15189 quality management system (QMS) or acceptable guidelines should be used Because accreditation is optional in India, where the majority of the population is served by resource-limited medical labs (RLML) of which only a tiny number are accredited, results provided by unaccredited labs may be tainted. To understand the significance of accreditation, accredited and non-accredited RLMLs were assessed for meeting the ISO15189:2012 QMS requirements. Fifty RLMLs, both accredited and unaccredited, from various Indian states, were evaluated for conformity with forty-one QMS criteria taken from ISO15189:2012. A chi-square test was employed to examine the RLMLs that satisfied each condition (p<0.005). A few accredited RLMLs failed to keep adequate records of clinical advice, risk assessments, independent work authorization for recruits, temperature-humidity monitoring, reagent acceptance-rejection, and updated reports. Non-accredited RLMLs met legal-entity (100%), had a laboratory manager (58%) and minimal records (51%); their P-value was non-significant (p>0.005). For the remaining criteria, chi-square testing with a p<0.005 was significant. Few accredited RLMLs' failures to comply may be attributed to routine procedural non-conformities discovered during their regular operations where the necessary documents were overlooked despite the lab's knowledge of the requirements. While the overwhelming majority of non-accredited RLMLs were found to have little to no knowledge of or awareness of many QMS requirements, demonstrating the need for standards. Accreditation enables the creation of acceptable, recognized laboratory practices.