Spinach (Spinacia oleracea L.) is a short-duration winter vegetable of increasing importance in Punjab, Pakistan. Viroflay, an open-pollinated semi-savoy cultivar of spinach, has shown vigorous growth in preliminary, non-replicated plantings in Dera Ghazi Khan, but its wider introduction into Punjab raises question about plant-health. Viroflay is the universally susceptible host in the international differential set for spinach downy mildew, caused by the obligate oomycete Peronospora effusa (Grev.) Rabenh., and is susceptible to all the 20 officially recognized races of the pathogen. This review summarizes current knowledge of P. effusa biology, seed-borne oospore transmission, race evolution and host-pathogen interaction, and evaluates these against the agro-climatic and production conditions of province Punjab. There is no race survey or confirmed record of spinach downy mildew from Pakistan in the literature. The cool Rabi growing season, rising winter rainfall reported for Dera Ghazi Khan, dense sowing, and reliance on imported seed are identified as the main factors that could favor introduction and establishment of the pathogen. A phased surveillance approach is proposed. Viroflay seed lots will be tested for oospores, unsprayed Viroflay strips will be used as sentinel plots for early detection, and any recovered isolates will be race-typed using the international differential set.  Although Viroflay's universal susceptibility limits its suitability for commercial production, the same characteristic makes it useful as a sentinel cultivar for detecting P. effusa and documenting its occurrence in Pakistan.