I thank Dr. Tom Schulenberg for his invitation to contribute to the Neotropical Birds project. Most of the information presented in this species account is derived from the research I have conducted on the Puerto Rican Nightjar starting in 1984 and the work of my former graduate student, Rafael González. Funding has been provided by the U.S. Fish and Wildlife Service's Caribbean Field Office. I am grateful to Dr. Wayne Arendt for sharing data on nightjar body measurements. I thank Miguel M. Canals, Guánica Forest manager and his staff, for their support and assistance over the years. I am also grateful to Wetzy Cordero, Susúa Forest manager and her staff for logistical support and use of facilities. Special thanks to Mike Morel for use of his outstanding collection of Puerto Rican Nightjar photographs. Additional photographs were provided by José A. Colón, Frank S. González, Derek Hengstenberg, and Armando Feliciano. José Silva of the Puerto Rico Conservation Trust provided access to the El Convento Reserve in the Guayanilla Hills. I am grateful to the Puerto Rico Ornithological Society (SOPI) and BirdLife International for funding support to update the geographic range of the species. I am indebted to the numerous caretakers and landowners who have granted trespass permission over the years. Finally, I dedicate this account to the memory of Dr. Phillip J. Zwank, mentor and friend, and Don Baudilio "Tuto" Hernández, former manager of Guánica Forest who guided biologists to the rediscovery of the Puerto Rican Nightjar in 1961.