Repeated pregnancy leaves young mothers nutritionally deprived which may in turn lead to poor infant growth. We measure the occurrence and persistence of stunting among offspring of young mothers who experienced repeated pregnancies using data from the Cebu Longitudinal Health and Nutrition Survey. We selected mothers aged 14-24 years (n = 1,033) with singleton birth. We determined the length-forage z scores (LAZ) at 12 and 24 months of the index child using the World Health Organisation 2007 growth standard. We fitted LAZ, stunting occurrence (i.e. LAZ < − 2) and persistence from 12 to 24 months into regression models and tested for the mediating effect of low birthweight and feeding practices. In these models, repeated pregnancy was analysed in an ordinal approach using number of past pregnancies of young mothers at birth of the index child. compared to infants born to young mothers aged 14-24 years who had no previous pregnancies, those born to young mothers with repeated pregnancies have at least 0.15 (95% CI − 0.23, − 0.08) LAZ lower and are at higher chance of stunting by at least 40% (95% CI 1.19, 1.67) at 12 and 24 months. Similar cohorts of infants showed an elevated risk of persistent stunting from 12 through 24 months with a relative risk ratio of 1.51 (95% CI 1.21, 1.88). Optimal feeding practices substantially mediated stunting outcomes by further reducing the effects of repeated pregnancy to stunting occurrence and persistence by 19.95% and 18.09% respectively. Mediation tests also showed low birthweight in the causal pathway between repeated pregnancy and stunting. Repeated pregnancy in young mothers is a predictor of stunting among children under 2 years. Secondary pregnancy prevention measures and addressing suboptimal feeding practices are beneficial to mitigate the negative impact of repeated adolescent pregnancy on children. Globally, stunting affects more than 100 million children under five 1 , and is associated with poor cognition, reduced school performance, immunodeficiency, and child mortality 2. In addition to adverse health outcomes, stunted children tend to have poorer economic productivity and lower wages in adulthood 3. These negative impacts make stunting, especially in 'the first 1,000 days' 4 , a profound indicator of poor health, social inequality, and disadvantage. The pathogenesis of stunting originates in the first 1,000 days, extending from early foetal development to 24 months after birth. Inadequate maternal nutrition and poor antenatal care can directly and indirectly result in an unhealthy intrauterine environment and poor foetal growth 5. Immediately following birth, suboptimal infant feeding practices slow offspring's growth rate 5. For example, sub-optimal (i.e. late, inadequate and inappropriate) complementary feeding negatively affects infant nutrition due to the rapid increase in nutritional needs after 6 months of age. Diarrheal infections and hygiene practices related to poor socioeconomic status (SES) can also lead to stunting due to nutrient malabsorption and h...