This study assesses the impact of adoption of improved seed yam technology (the minisett technology) on yam yields and the income of smallholder farmers in the northwest region of Cameroon. This technology has the potential to increase yam yields by a factor of 2 to 3 compared to traditional techniques, however, adoption by smallholder farmers in Cameroon has so far been low. Survey data was collected from a total of 394 randomly sampled farmers in three of the five administrative divisions of the northwest region. Of this total sample a sub-sample of data from 274 farmers who had been exposed to the technology was analyzed using propensity score matching (PSM) and employing a variety of different matching algorithms that take into account counterfactuals and potential impact. PSM is a quasi-experimental research design which was adopted because it is known to address problems of selection bias resulting from sampling and self-selection issues. The results show that the adoption of the minisett technology has a positive and significant (p<0.01) effect on yam yields. We also find that this increase in yam yield is partly due to; the use of good agronomic systems (such as proper weed control practices and the use of stakes), access to information through farmer organizations, and access to the support provided by extension and research services. We also found a positive and statistically significant (p<0.01) effect of adoption on household income. With the adoption being more likely to have a positive and significant effect on household incomes of farmers that have access to fertilizers and those that are affiliated to farmers' organizations. Our results highlight the need to encourage the use of innovative agricultural technologies to boost crop production and the household incomes of smallholder farmers in Cameroon. This can be achieved provided appropriate measures are taken to facilitate access to agricultural inputs (especially fertilizers and stakes). Farmers should also be encouraged to employ good agronomic practices. The extension and research services should make use of existing farmers' organizations to enhance their capability of capturing potential adopters.