Reforestation programs are a common policy response among developing country governments in the tropics attempting to deal with environmental and economic problems caused by widespread deforestation. The objective of this paper is to examine participation by small-and medium-sized farms in two reforestation programs undertaken in recent years by one country, Costa Rica, which has been at the forefront of developing country environmental protection efforts. Analysis of a survey of 243 program participants and non-participants shows that farm households participating in reforestation programs had generally larger farm sizes, were dedicated to low labor-intensive, land-extensive agricultural activities, faced significant family on-farm labor constraints, were more heavily dependent on off-farm income sources, and had more extensive contact with local extension efforts. Logistic regression is employed to econometrically identify demographic, economic, and land use determinants of farm household participation in reforestation programs; the implications of these findings are analyzed. The limitations of reforestation programs, especially with regard to management factors and quality of reforested plots, are reviewed. Implications for improving the efficiency of reforestation programs and the merits of other policy alternatives are also discussed.