The solar energy produced by Scheffler parabola (10 m2), is not fully exploited by solar distillation system of Aromatic and Medicinal Plants. In this work, the optical losses in the primary and secondary reflectors, and the thermal losses at each part of this system (distillation still, steam line, condenser) were determined. A thermal energetic and exergetic analysis was also performed for a solar system distillation of rosemary leaves. For average intensity radiation of 849.1W/m2 and 6 Kg of rosemary leaves during 4 hours of distillation, exergy and optical efficiencies of the system achieved up to 26.62% and 50.97%, respectively. The thermal efficiency of the still, steam line and condenser is about 94.80%, 93.08%, and 87.76%, respectively. Total efficiency of the solar distillation system, taking into account the heat losses in the still, steam line, and condenser, as well as the optical losses in the two reflectors, is 39.49%. The efficiency can be as high as 42.42% and if the steam line is insulated. Moreover, the comparison between the Solar Steam Distillation and Conventional Steam Distillation shows that solar distillation is much more efficient since it gives better results, and especially it avoids emission of 12.10 kg of CO2 during extraction.