Geographic range of the jaguar (Panthera onca) in Mexico has decreased due to illegal hunting, loss of prey, and loss of habitat. No survey of jaguars has been conducted in San Luis Potosí since 1953, despite potentially suitable habitat in the Sierra Madre Oriental. During May 2006–March 2008, we conducted 22 field surveys, including interviews of local officials, residents, landowners, and hunters from 42 communities, and searched for tracks near each location where jaguars were reported in the Huasteca Region of the Sierra Madre Oriental of San Luis Potosí. We obtained 34 records of jaguars, 28 considered as recent records comprising ≥12 individuals and 6 historic records. Jaguars were recorded in oak forest (31.1% of records), tropical deciduous forest (28.1%), cloud forest (12.5%), tropical forest (12.5%), piedmont scrub (9.4%), pine-oak forest (3.1%), and along a border between a sugar cane plantation and tropical forest (3.1%). Locations were 150–2,400 m in elevation. We documented presence of diverse prey and four other species of felids. We generated a distribution map for jaguars and estimated loss of forests for 1970–2000. Geographical distribution of jaguars in San Luis Potosí extends north (22°30′N) to the municipality of El Naranjo, south (21°24′N) to the municipality of Xilitla, east (98°54′W) to the municipality of Ciudad Valles, and west (99°34′W) to the municipality of Rayón. The distribution comprises the subprovince of the Gran Sierra Plegada, Carso Huasteco, and Sierra del Abra Tanchipa of the Sierra Madre Oriental. Given the number of records and quality of remaining habitat, the Sierra Madre Oriental in San Luis Potosí should be considered as a high priority for long-term conservation of jaguars in Mexico.