The leaf oils of the leaves of twoPelargoniumspecies,P. papilionaceumL. L'Herit. andP. vitifoliumL. L'Herit. (Geraniaceae) and a cultivar ‘Sweet Rosina,’ were found to contain citronellic acid, ranging from 27.9% to 89.3%. The essential oils were obtained by both steam distillation and using solvent extraction in both hexane and petroleum spirit and the citronellic acid was identified by comparison with a standard using GC and also GC/MS. The presence of citronellic acid has not been reported inP. papilionaceumbefore and its occurence in the cultivar ‘Sweet Rosina’ cannot be explained as both parents were devoid of the acid.