The aim of the present work was to establish a proper high-performance thin-layer chromatographic (HPTLC) method for the quantification of linalool and myristicin from leaf extracts of parsley, dill, and celery grown in microwave fields. In order to establish the influence of stress induced by microwave irradiation on plants, the plants selected for the study were subjected to irradiation with microwaves within two microwave frequency domains: GSM (mobile communication) and WLAN (wireless internet connection). The HPTLC analyses were performed in a normal chromatographic chamber on silica gel 60 plates, using petroleum ether—dichloromethane (30:70, v/v) as mobile phase. Photodensitometric evaluation of the chromatographic plates was carried out at 600 nm after spraying with vanillin reagent. The developed method was validated in terms of selectivity, linearity, limits of detection and quantification, precision, and accuracy.