It is known that most chemicals, which have been increasingly used since ancient times, have carcinogenic and mutagenic effects. As an alternative to these chemicals, natural compounds, such as plant growth regulators (PGRs) have been used. However, are the PGRs used to obtain efficient plants in agriculture as harmless as it is thought today when it is essential to access natural foods in the food and agriculture sectors? Therefore, this study investigates the mutagenic activity of two plant growth regulators (Kinetin, Chlormequat chloride (CCC)) using the Ames/Salmonella short-time test system. Experiments were performed in the presence (+ S9) or absence (-S9) of metabolic activation enzymes using TA 98 and TA 100 strains of Salmonella typhimurium. 5 non-cytotoxic doses for each test substance were investigated. The results were evaluated by comparing them with spontaneous control plates. According to the results, a 2500 μg/plate dose of Kinetin was to be found mutagenic on the strain TA 98 in the presence and in the absence of S9 enzyme, and on the strain TA 100 in the absence of the S9 enzyme. The other substance CCC did not cause mutagenic effects on the bacterial strains.