This work was aimed to determine the moisture content from Eucalyptus (Eucalyptus Citriodora) and Spearmint (Mentha spicata) leaves, as well as qualitative and quantitative analysis of volatile organic compounds (VOCs), released during the drying process. Sun and oven drying were used to determine the moisture content from the Eucalyptus and Spearmint leaves. Controlled, Solar, and Soxhlet distillation systems used to collect the volatile organic compounds (VOCs) from the fresh and dried leaves. Gas chromatography (GC) used to perform the qualitative and quantitative analysis of the VOCs. The result showed that the moisture contents of the Eucalyptus leaves were 53% and 56.2%, and Spearmint leaves were 62.5% and 77.3%, respectively. Furthermore, GC analysis using controlled and solar distillation systems for fresh leaves 14 and 10 (from Eucalyptus), and 6 and 4 (from Spearmint) volatiles were detected respectively whereas, soxhlet distillation system for dried leaves 4 and 4 volatiles were found only from both plants. The considerable difference in the number of volatiles from fresh and dried leaves is due to the missing volatiles were released during the drying process for becoming atmospheric pollutants as well as human toxicity and also resulted in the loss of functional properties of products e.g., nutritional and medicinal values. So, we conclude that the methodology adopted in this study is ample to collect and determine the volatiles/bio ingredients from the different perishable plants, as well as quantify and qualify each biochemical compound among the volatiles. [ABSTRACT FROM AUTHOR]