The data are the phenotypic host reactions of a recombinant inbred line population of Capsicum annuum developed to differentiate races of Phytophthora capsici. The New Mexico Recombinant Inbred Line (NMRIL) is an F8 population derived from a hybridization between Early Jalapeno (susceptible parent) and Criollo de Morelos 334 (CM334) (resistant parent). The controls include CM334 (negative control) and New Mexico Capsicum Accession 10399 (NMCA10399) (positive control). Also included are the World Vegetable Center host differentials including Early Calwonder (EC), PI 201234, PBC137, and PBC602. The host differentials were screened with isolates of P. capsici that were collected from chile pepper production regions of Taiwan (Republic of China) in 2016 as well as Race 1, 2, and 3 of P. capsici from the World Vegetable Center collection at a concentration of 10,000 zoospores per plant. The plants were scored at ~2 weeks after inoculation and only those with an average score of = 1 were considered resistant. The experiment included 6 plants per replication with two replications and each test was repeated twice. The data would be best used by individuals interested in population structure, virulence, or sources of resistance to the oomycetes plant pathogen Phytophthora capsici.