The objective of this study was to (1) to describe the relationship between chinook conditions and illness related behaviour in women, aged 20-49 years, and (2) to examine the possibility of the existence of subgroups of chinook-sensitive women. At present no empirical evidence is available regarding a relationship between chinook conditions and illness related behaviours. This study comprises the secondary analysis of a large survey of various health and health-related factors of urban women aged 20-49 years, carried out in 1985-1986 in Calgary. The interview date was used to link behaviours to chinook conditions. We found no evidence of a significant relationship between the behaviours investigated and chinook conditions in the general population. However, the data strongly supported the concept of chinook sensitivity. Women with a history of chronic health problems were more likely to visit a health care professional on chinook days than healthy women and women in the subgroup aged less than 35 years cut down their usual daily activities during chinook conditions. Women with a history of recurring migraine headaches were less likely to take prescription medication on chinook days, and women with a history of emotional disorders were more likely to have higher scores on the accident scale and to report bursts of energy or excitement during chinook days. More research is needed to identify subgroups of susceptible persons, as well as to determine whether chinook sensitive persons are equally susceptible to weather changer of other types.