Declining soil fertility largely explains the gap between actual and potential yield among smallholder farmers in sub-Saharan Africa. This study investigates the relationship between yield variability in smallholder commercial kale (Brasica oleracea) production in Kenya and farmers’ attitudes for integrated soil fertility management (ISFM) as well as the relationship to a domain-specific risk-benefit preference scale. Data was collected from 125 peri-urban commercial kale farmers through personal interviews conducted by trained enumerators using a pre-tested questionnaire. Results of ordinary least squares regression indicate that farmers with strong attitudes in favour of ISFM experience decreased variability in yields. A significant negative relationship was observed between farmers expectation of benefits associated with soil fertility management technologies and yield variability. Farmers’ risk perception associated with the use of nonconventional soil fertility management practices, particularly the use of human faecal manure, increase variability in yields. However, risk perception associated with the use of conventional soil fertility management practices including application of animal manure, chemical fertilizers, crop rotation and use of crop residues significantly reduce yield variability. Individual farmers base their choice of ISFM practices on their assessment of both risks and benefits. It is argued, therefore, that in order to scale-up adoption of ISFM, policy should focus on increasing farmers’ access to information on the benefits associated with the practices while improving farmers’ perceptions of the risks associated with the use of non-conventional technologies such as human faecal manure by addressing farmers’ health concerns.