An estimated 40% of potential global crop production is lost annually to pests and diseases. Reducing this level of crop loss is critical to increasing agricultural productivity, which is essential in achieving the sustainable development goals of zero hunger and no poverty. However, the lack of access to timely and relevant advice on crop health problems poses a significant challenge to farmers to take action at the right time to mitigate crop losses. In efforts to address this issue, over 4000 plant clinics have been established in 34 countries worldwide where farmers who are struggling with plant pests and diseases can take samples of their ‘sick’ crops to trained plant doctors for diagnosis and plant health advice. The plant clinic initiative began in 2003, but thus far, there has not been a rigorous assessment of the impact of this innovative approach of delivering targeted agricultural extension services. Using a recent panel survey of smallholder maize producers in rural Rwanda, this paper attempts to address this gap by analysing the impact of plant clinics on farm performance (measured by technology adoption, and maize yield and income) and on poverty alleviation (measured by the Progress out of Poverty Index). Employing the correlated random effects estimation methods to account for unobserved heterogeneity, we find that plant clinics significantly increase the adoption of crop protection technologies to control devastating maize pests, such as fall armyworm and maize stalk borer, and this, in turn, results in significant maize yield and net income gains of 28% and 23%, respectively. We also show that seeking plant health advice from plant clinics is significantly associated with a 5% reduction in the likelihood of a household falling below the extreme poverty line of $1.25 per day. The results imply that policies and programmes aimed at promoting the establishment of and farmers’ participation in plant clinics can contribute to increased agricultural productivity and poverty reduction.