Motivation - Although increasing agricultural production is necessary to feed a growing population and meet changing dietary preferences, basing this on expanding area cultivated at the expense of the forest is unsustainable. Expanding agriculture area into forests accounts for 80% of the deforestation globally. Zambia is estimated to lose between 167,000 and 300,000 ha of total forest per annum. Deforestation contributes to climate change, which in turn disproportionately affects smallholder farmers who depend on rainfed agriculture and yet have the least means to adapt to and cope with climate shocks. Climate-smart agriculture (CSA) is considered a necessary condition to increase agricultural productivity and resilience, as well as to adapt to and mitigate climate change. However, the pathways through which CSA can reduce deforestation are neither obvious, nor are they well understood. At conceptual level, the Borlaug hypothesis postulates that increasing agricultural productivity enables intensification, which in turn spares nature. However, increasing agricultural productivity makes agriculture profitable, which in turn might incentivize rather than reduce deforestation—a phenomenon called the Jevons Paradox. Understanding the different conditions and enabling environments for either of the opposing outcomes in different contexts remains an unresolved and important empirical regularity. Purpose: This paper aims to contribute towards a better understanding of the linkages among CSA, cropland expansion, and deforestation. It unpacks how, why, and where cropland expansion is occurring among smallholder farmers in Zambia. Approach and Methods: Based on detailed nation-wide household-level data, we use an instrumental variable approach to assess cropland expansion and drivers of that expansion, and assess whether CSA reduces cropland expansion in Zambia. We supplemented this analysis with the spatially-explicit Hansen et al. (2013) data to characterize district-level forest cover changes between 2001 and 2018 and correlate these data with district-level changes in cropland expansion to identify processes and patterns. Findings: One-fifth of the 7,241 farm households surveyed in 2019 expanded cropland between the 2016/2017 and 2017/2018 farming seasons, clearing on average 0.18 ha, but only 13% expanded their cropland into forests, clearing an average of 0.10 ha of forestland per household. While not all cropland expansion necessarily leads to deforestation, smallholder cropland expansion into forests represents about 4.6% of cultivated land and about 60% (or 150,000 ha) of the 250,000 ha of forests lost per year in Zambia. Most households expanded cropland because of the need to meet subsistence food needs and a few others in response to market opportunities. Much of the cropland expansion among smallholder farmers is concentrated in Luapula, Muchinga, Northern, North- Western, and Western provinces, which are among the most agriculturally favorable areas given the good rainfall conditions (except for Western Province). However, these provinces have high soil acidity, further bringing to the fore a need to address soil health in these areas. Adopting CSA had no statistically significant effect on cropland expansion in our national sample, indicating that CSA alone might not avert expansion-led deforestation. However, age and education are associated with reduced expansion, while secure tenure, landholding size, being male-headed, and distance from the plot to the homestead are positively related to cropland expansion. Thus, CSA-led (technological) intensification alone might not reduce deforestation unless if complemented with improved natural resources management, which would control conversion of forestland to other uses, including agriculture. Policy Implications: We draw three implications for policy. First, relying only on technological-driven intensification to spare forests may be risky. Productivity-enhancing agricultural technologies, like CSA, would be more likely to lead to win-win outcomes for conservation and food production if accompanied by improved resource governance initiatives and better land use planning. Second, seeing that smallholder-led expansion accounts for about 60% of the reported deforestation in Zambia—and most of this expansion occurs in the current agricultural belt—signals the urgency with which policies are required to curb expansion. This is important in order to avert the likelihood that the current agricultural belt, which receives abundant rainfall in Zambia might start to experience reduced rainfall due to deforestation-induced climate variability. And, lastly, we contend that concerted efforts are needed to identify sustainable and efficient ways to scale-up and scale-out CSA adoption in Zambia and the region, given the strategic role CSAs play in building climate resilience.