The essential oil of leaves and peel from the Cretan variety Zambetakis (Citrus limon) was obtained by steam distillation with a Clevenger apparatus. The essential oil was subjected to GC-MS analysis, and 35 substances were identified. The main component in both essential oils was limonene. beta-Pinene, myrcene, neral, geranial, neryl acetate, geranyl acetate, and beta-caryophyllene have been identified in the leaf oil. The peel oil contained gamma-terpinene, beta-pinene, myrcene, neral, and geranial. The quantification of volatile substances was based on the internal standard method, using octyl acetate as internal standard, and expressed in milligrams per kilogram of the essential oil. The high contents of neral and geranial were indicative of the high quality of both essential oils. The aroma profile and quantitative variations among the essential oil components were measured at six different time intervals over a period of greater than one year. Differences between the components of lemon leaves and peel were observed.