Gender differences in the trend of educational inequality in hypertension have been observed especially in the Asian populations, indicating the increasing importance of education as a social determinant of hypertension among women. This study examined the gender-specific trends of educational inequality in physician-diagnosed hypertension in Hong Kong between 1999 and 2014. Based on a series of eight government-led territory-wide household surveys conducted between 1999 and 2014, 97,481 community-dwelling Hong Kong Chinese adults aged 45 or above were analysed. The extent and trend of gender-specific educational inequality in self-reported physician-diagnosed hypertension were estimated by regression-based Relative Index of Inequality and age-standardised Slope Index of Inequality. Over the study period, age-standardised prevalence of self-reported hypertension increased in both genders, with the greatest prevalence among the least educated women. Educational inequalities in hypertension significantly widened in female from 1999 to 2009 and persisted thereafter; nonetheless, the respective inequality was negligible in male. Further adjustment for household income did not attenuate the observed inequality. To conclude, a widened and then persistent discrepancy in hypertension across education levels was observed among women, but not among men, in Hong Kong. The gender perspective should be carefully considered when designing hypertension prevention strategies and related health policies.