The yield and composition of sage (Salvia officinalisL.) oil cultivated in northern Italy and subjected to different growing conditions (planting densities and harvest managements) were evaluated. Sage harvested in spring at flowering stage (1st cut) gave the highest yields of fresh and dried matter. A harvesting regimen with three successive harvests produced the highest biomass yield. Twenty-nine compounds were identified in the oil. The oil of sage harvested at flowering stage greatly differed in composition from the oil of sage cut at vegetative stage. Very important differences were observed also between the oil composition of sage harvested at vegetative stage in spring and in the autumn. The highest content of thujones was found in the oils of sage harvested in autumn.