Background: In the recent years new techniques were applied for extraction and isolation of natural phytochemicals from living organisms by using microwaves to assist extraction, decrease the time and cost of isolation methods in the same time these methods must guarantee the highest yield from the plants.

Objectives: this research aimed to evaluate two methods of volatile oils extraction, the microwave accelerated distillation and hydrodistillation also to find the best source of Rue oil Ruta graveolens or Ruta chalepensis leaves. In this research, the effect of microwave power on the yields of volatile oils in R. graveolens and R. chalepensis is the first time proven in the literature.

Method: Microwave accelerated distillation was applied for the extraction of volatile oils from the leaves of Ruta graveolens and Ruta chalepensis. The microwave assisted extraction method had been compared with hydrodistillation conventional technique, in terms of extraction yields, cost and time.

Results: The volatile oils of the dried Ruta graveolens collected from the Jerusalem area of Palestine were recovered by microwave accelerated distillation method with approximately 2.2% yield in Ruta graveolens and approximately 1.8% yield of the volatile oils in Ruta chalepensis on a dry weight basis, in the same time the yield was approximately 1.2% in Ruta graveolens while was 0.6% yield of the volatile oils in Ruta chalepensis by using hydrodistillation method.

Conclusion: The results showed that the isolation of the volatile oils from R. graveolens and R. chalepensis by microwave assisted extraction is more efficient in time cost and yield rather than hydrodistillation; also the results showed that the best economical source for Rue oil is R. graveolens for food, cosmeceuticals and pharmaceutical industries.