In order to evaluate the proper concentration of plant growth hormone and the suitable plant growth hormone in Rosmarinus officinalis L., a significant fragrant, medicinal, and herbaceous plant, the study was carried out in a greenhouse setting during the vegetative period of 2022. In the experiment, peat and vermicompost mixture (3 peat / 1 vermicompost) as the rooting medium, Indole acetic acid (IAA), Indole butyric acid (IBA), and Naphthalene acetic acid (NAA) hormones as plant growth regulators and 0, 1000, 2000, 3000, 4000 ppm concentrations of these hormones were used and the Randomised Plot Experiment Design were established three times in the Multiple Comparison Test “LSD”. In seedlings removed three months after planting, properties such as seedling height (cm), number of roots (pieces), root length (cm), maximum root length (cm), number of laterals (pieces) and lateral length (cm) were examined. The highest seedling length (19.88 cm) and number of shoots (12.60 pcs), 3000 ppm concentration of Indole acetic acid (IAA), root length (16.30 cm), and 3000 ppm concentration of Naphthalene acetic acid (NAA) at the highest root length (22.82 cm) came to the fore. In terms of root number, the values found at 3000 ppm concentration of indole acetic acid (19.25 pieces) and naphthalene acetic acid (20.09 pcs) were combined into one statistical group and made up the maximum number of roots. The lateral length control seedlings statistically prevented other applications and produced the highest lateral length (1.99 cm). Therefore, it can be said that Indole acetic acid (IAA) and Naphthalene acetic acid (NAA), both of which have a concentration of 3000 ppm, are the most suited growth hormones.