This study uses panel data from 384 Thai rural farm households collected annually from 2000-2013 to examine the determinants of household s land rental market participation, and the impacts of renting land on household incomes. A preliminary finding indicates that households with relatively poor land endowment cultivate more land than do other households to the extent that more than half of the land is rented in. Consistent with previous literature, the study find evidence that land rental markets in Thailand promote farm productivity and reduce landholdings inequality by transferring land from less-efficient to more-efficient households and from land-abundant to labor-constrained households, respectively. More importantly, the rental markets significantly raise the net farm incomes of tenants, most of whom are land-constrained households. Mechanisms to reduce land conflicts and remove local restrictions on land rental are needed in order to improve the functioning of land rental markets, and thereby enhancing farm income. Key Words: Land rental market, household income, Thai agriculture, Townsend Thai data Acknowledgement : This study is fully supported by Thailand Research Fund (TRF); project reference code RDG5920034. The author would like to thank Charapon Chantorn and Piyayut Chitchumnong as well as two anonymous reviewers assigned by TRF for their valuable comments and suggestions.