Limited research considers change over time for drowning mortality among individuals under 20 years of age, or the sub-cause (method) of those drownings. We assessed changes in under-20 drowning mortality from 2000 to 2013 among 21 countries. Age-standardized drowning mortality data were obtained through the World Health Organization (WHO) Mortality Database. Twenty of the 21 included countries experienced a reduction in under-20 drowning mortality rate between 2000 and 2013, with decreases ranging from -80 to -13%. Detailed analysis by drowning method presented large variations in the cause of drowning across countries. Data were missing due to unspecified methods in some countries but, when known, drowning in natural bodies of water was the primary cause of child and adolescent drowning in Poland (56-92%), Cuba (53-81%), Venezuela (43-56%), and Japan (39-60%), while drowning in swimming pools and bathtubs was common in the United States (26-37%) and Japan (28-39%), respectively. We recommend efforts to raise the quality of drowning death reporting systems and discuss prevention strategies that may reduce child and adolescent drowning risk, both in individual countries and globally.