This study examines the geographic variation in the incidence of HIV/AIDS in Chiang Rai, one of the northern districts of Thailand with a very high rate of HIV infection and AIDS. A related goal of this study is to understand the socioeconomic impact of the disease. First, spatial analysis is used to estimate the effects of local determinants on the incidence of HIV and AIDS. Second, standardized questionnaire surveys of patients are conducted to understand the individual context of the disease. Finally, in-depth qualitative interviews are used to examine the socioeconomic impact of the disease at the individual level. Results show that localities with a relatively high percentage of households engaged as laborers, localities close to municipal areas, and those with a high concentration of commercial sex workers are significantly correlated with high incidence rates. Places close to municipal areas are typically more urbanized, with diverse income groups and businesses in their vicinity. These areas have higher levels of risk factors compared to places that are remote. The interview-based analysis shows that HIV/AIDS patients, from diverse education and income backgrounds and different levels of comfort with disclosure and disease intensity, have shown equally diverse levels of suffering and coping strategies. Their response is not only dictated by the intensity of the disease but by their own acceptance of their disease status, an understanding of the disease and treatment options, their fear of stigma, and the reaction of family, friends, partners, and health workers. Key Words: HIV and AIDS, local determinants, socioeconomic impact, Thailand.Este estudio examina la variación geográfica de la incidencia de HIV/SIDA en Chiang Rai, uno de los distritos del norte de Tailandia que registra altas tasas de infección de HIV y SIDA. Otro de los propósitos del estudio es comprender el impacto socioeconómico de la enfermedad. Primero, se utilizó el análisis espacial para calcular los efectos de determinantes locales sobre la incidencia de HIV y SIDA. Segundo, se llevaron a cabo observaciones sistemáticas de pacientes por medio de cuestionarios estandarizados, para entender el contexto individual de la enfermedad. Y, finalmente, se aplicaron entrevistas cualitativas a fondo para examinar el impacto socioeconómico de la enfermedad a nivel individual. Los resultados muestran que aquellas localidades con un porcentaje relativamente alto de familias de trabajadores, localidades cercanas a lasáreas municipales y aquellas con una alta concentración de trabajadoras sexuales, están significativamente correlacionadas con tasas de alta incidencia. Los lugares cercanos a los poblados son típicamente más urbanizados, tienen grupos de ingresos diversificados y negocios en la vecindad. Estasáreas tienen los factores de riesgo de más alto nivel, en comparación con los lugares remotos. El análisis de los datos generados en entrevistas muestra que los pacientes de HIV/SIDA con antecedentes variados en educación e ingreso y diferentes nive...