By 2012 HIV had infected about 1.6 million Kenyans and an estimated 58 000 had died due to HIV/AIDS. HIV/AIDS
rates in western Kenya are disproportionately high compared to the rate in Kenya as a whole. This study aimed to
assess gender differences in participation in collective action in households affected by serious illness (e.g., HIV/
AIDS, TB) in western Kenya. We expected serious illnesses would reduce collective action due to a reduction in the
number of adults and their ability to care for themselves and others. We used data from a mixed-methods study
that used multiple-case embedded-case studies for rural households in western Kenya. The study investigated
the relationship between collective action and households affected by serious illnesses. Household health was
assessed from information about seriously ill members in 120 households. This information was compared with
data about collective action activities and demographic data. Nearly half (48%) the households reported serious
illness. More than 1 in 4 (28%) had HIV/AIDS, TB or AIDS-associated illnesses. Women engaged in a moderate
level of participation in collective action groups and were statistically more likely to report serious household
illness (OR = 8.08, 95% CI 2.89, 22.56). Men, who were moderately (OR = 3.24, 95% CI 1.27, 8.25) or highly involved in
collective action groups (OR = 15.43, 95% CI 1.30, 183.06), were statistically more likely to report serious household
illness. Collective action groups may help households cope with illness and should be encouraged in communities
hard hit with serious illness.