Pearl millet downy mildew, also known as pearl millet leprosy, green ear disease, or witch’s broom, is caused by the pathogen Sclerospora graminicola (Sacc.) Schroet and is the most devastating disease affecting pearl millet. It can cause grain yield losses of 20 to 40%. The study evaluated the effect of sowing date on pearl millet downy mildew infection at the CERRA in Maradi during the 2025 winter season. The experimental design consisted of a single block repeated three times according to three (3) sowing dates: July 1, 14, and 24, 2025. The spacing between blocks is 2 m. Each block consists of 256 millet plots covering an area of 225 m2. Within each block, five (5) subplots, each consisting of 9 millet plots, are laid out in an X-shaped pattern. The plant material used consisted of a single variety of pearl millet, HKP. At physiological maturity, the incidence, severity, and impact of downy mildew were recorded on the nine (9) plots of each experimental plot, and after harvest, biomass, ear, and grain yields were determined. The results revealed that early-sown crops suffered less from downy mildew, exhibiting the lowest rates of incidence (1.82%), severity (0.9%), and impact (2.22%), compared to 41.67%, 26.11%, and 20.73% for late-sown crops. Furthermore, the highest yields were obtained at the first sowing date, with biomass, ear, and grain yields of 745.4 kg ha⁻1, 673.3 kg ha⁻1, and 442.2 kg ha⁻1 respectively, compared to 483.6 kg ha⁻1, 443.6 kg ha⁻1 and 277.6 kg ha⁻1 on the third sowing date. This study shows that late sowings were subject to greater pressure from downy mildew, causing a considerable decline in yields. Thus, for ecological management of downy mildew in millet, early sowing is recommended.