Nocturnal nucleation events were observed from July 2005 to October 2006 in Tumbarumba in New South Wales, Australia. These events were observed on one third of the nights and they were often much more intense than normal daytime events. One of the main features found in this environment was the abundance of eucalyptol among the volatile organic compounds (VOC) emitted by the local Eucalypt forest. In contrast, in most other forest environments, such as Hyytiälä in southern Finland, eucalyptol is a minor component of VOC emissions. Therefore, the objective of this study was to evaluate the role of eucalyptol in the nocturnal nucleation events. For this purpose, a series of experiments and quantum mechanical calculations were performed. Both approaches showed that the role of eucalyptol in the nocturnal events can be ruled out.