Application of film antitranspirant to wheat during late stem extension reduces drought damage to yield, but the mechanism is unknown. Field experiments under rain shelters were conducted over 3 years to test the hypothesis that film antitranspirant applied before meiosis alleviates drought-induced losses of pollen viability, grain number and yield. The film antitranspirant di-1-p-menthene was applied at third-node stage, and meiosis occurred at the early boot stage, with a range of 11–16 days after spray application in different years. Irrigated, unsprayed plots were included under the rain-shelters, and pollen viability, measured in 2 years in these plots, averaged 95.3%. Drought reduced pollen viability to 80.1% in unirrigated, unsprayed plots, but only to 88.6% in unirrigated plots treated with film antitranspirant. Grain number and yield of irrigated plots, measured in all years, were 16 529 m^–2 and 9.55 t ha^–1, respectively, on average. These were reduced by drought to 11 410 m^–2 and 6.31 t ha^–1 in unirrigated, unsprayed plots, but only to 12 878 m^–2 and 6.97 t ha^–1 in unirrigated plots treated with film antitranspirant. Thus compared with unirrigated, unsprayed plots, antitranspirant gave a grain yield benefit of 0.66 t ha^–1. Further work is needed to validate the pollen viability mechanism in different climatic zones and with a wide range of cultivars.