A number of case studies have shown that promotion of breastfeeding (BF) coincides with improved BF and exclusive BF (EBF) practices. We quantify the relationship between BF promotion and changes in BF practices by analyzing the relationship between implementation of the WHO/UNICEF Global Strategy for Infant and Young Child Feeding as measured by the World Breastfeeding Trends Initiative (WBTi) and trends in EBF and BF duration over the past 20 y in 22 countries in Africa, Asia, the Middle East, and Latin America. The median annual increase in EBF was 1.0%/y in countries in the upper 50th percentile of WBTi scores, indicating national policies and programs most consistent with WHO/UNICEF recommendations, whereas the median increase in EBF was only 0.2%/y in countries with the lowest WBTi scores (P = 0.01). The median annual increase in BF duration in all countries was <0.1%/ y. The annual increase in EBF was not associated with maternal demographic factors, such as urban residence, paid maternal employment, maternal education, or gross national income. Our results show that the association between BF protection, promotion, and support and improved EBF is measurable and strengthened by case studies possibly causal.