Salicylic acid (SA) may induce toxicity in orchids depending on its concentration and the plant species, but there is no information about the effect of this substance on orchids cultivated in vitro. The objective of the present study was to evaluate the effects of different concentrations of SA on Cymbidium atropurpureo and Phalaenopsis Golden Peoker cultivated in vitro to verify the biological losses caused by the substance’s toxicity. The orchids Cymbidium atropurpureo and Phalaenopsis Golden Peoker were sown in vitro in a Murashige and Skoog (MS)-growth medium and transferred to a medium of the same type containing SA 90 days after sowing. The studied SA concentrations were 0, 50, 100, 200, 300, 400, 500, and 1000 µmol·L⁻¹, and the plants were kept in this medium for 210 days. The treatments were distributed into a completely randomized design with four replications. Biometric variables of the seedlings and electrolyte leakage were evaluated 300 days after sowing. The results indicate that the addition of SA interfered with the in vitro growth and development of seedlings of Cymbidium atropurpureo and Phalaenopsis Golden Peoker, given that it caused all the examined variables to show reduced values and triggered electrolyte leakage, consequently inducing toxicity.