Abstract The most applicable method for extraction of essential oil is hydro-distillation. It is a traditional technique which is used in most industrious companies. Microwave-assisted hydro-distillation (MAHD) is an advanced hydro-distillation (HD) technique utilizing a microwave oven in the extraction process. MAHD of essential oils from the aerial parts (leaves) of rosemary (Rosmarinus officinalis) was studied and the results were compared with those of the conventional HD in terms of extraction time, extraction efficiency, chemical composition, quality of the essential oils and cost of the operation. Microwave hydro-distillation was superior in terms of saving energy and extraction time. Gas chromatography–mass spectrometry was used for analysis of quantity of the extracted essential oils. Also microwave hydrodistillation was found to be a green technology.
