The composition of essential oil of Ledum palustre L. was investigated. This oil was obtained by steam distillation of leaf material from plants growing in the Hortus Botanicus at Haren (Groningen). It was separated into seventeen fractions by column chromatography on silicagel and gradient elution with mixtures of petrol (bpt. < 40 degrees C) and diethylether. The investigation was made by GLC and GC-MS. In total, 80 components were identified. About 50 constituents were new, including vitispirane, perillaalcohol, perilla-aldehyde, isopinocamphone, germacrone, etc. Principal components are ledol, palustrol and myrtenal.