Background <p>Light is essential for producing high-quality plants. The advancement of light-emitting diode technology has unlocked new opportunities for growing plants in controlled settings. In this study, the effects of light-emitting diodes priming and drought stress on some physiological and biochemical parameters were studied in two <i>Melissa officinalis</i> genotypes (Ilam and Isfahan) one and three weeks after drought stress. The experiments were conducted in a factorial arrangement within a completely randomized design with three replications.</p> Results <p>Drought stress reduced growth indicators such as fresh and dry weights of aerial parts, leaf number, and relative water content. Light-emitting diode priming relieved such reductions in both genotypes. The accumulation of phenolic compounds, anthocyanin, and levels of proline, along with the activity of the enzyme phenylalanine ammonia-lyase, increased under drought stress, with the maximum increase achieved under red + blue and blue light-emitting diode light-primed plants. Especially in the Ilam genotype, phenylalanine ammonia-lyase enzyme activities and the accumulation of phenolic compounds were remarkably enhanced by the use of red + blue light-emitting diode light. Also, abscisic acid showed higher values under drought stress and the highest in pre-treatments with red + blue and red light-emitting diodes.</p> Conclusion <p>The effects of different treatments on the physiological indices showed that drought tolerance in <i>Melissa officinalis</i> was improved due to the priming of red + blue light-emitting diode in both genotypes. Thus, our results emphasized the use of light-emitting diode priming as a useful method to enhance the drought resistance of medicinal plants.</p>