Multiple forms of malnutrition coexist in infants and young children (IYC) in Peru. The World Health Organization has proposed double-duty actions (DDAs) to simultaneously address undernutrition and overweight/obesity. We assessed current implementation of- and priority for- government-level actions to tackle multiple forms of malnutrition in IYC in Peru. Mapping of current policy activity was undertaken against 47 indicators of good practice for five DDAs (exclusive breastfeeding, complementary feeding, food marketing, maternal nutrition, preschool nutrition; assessed by 27 indicators) and for the enabling policy environment, i.e., ‘infrastructure support’ (health in all policies, platforms for interactions, financing, monitoring, governance, leadership; assessed by 20 indicators). Interviews with 16 national experts explored views on the level of and barriers to implementation of DDAs and infrastructure support, as well as their prioritisation based on likely impact and feasibility. The level of implementation of actions was categorised into two groups (agenda setting/formulation vs. implementation/evaluation). Mean scores were generated for prioritisation of DDAs and infrastructure support. Deductive qualitative analysis was undertaken to identify barriers that influence policy implementation. Only 5/27 DDA indicators were reported as fully implemented by all national experts ( international code that regulates the marketing of breastmilk substitutes , iron supplementation for IYC , micronutrient powders in IYC , iron/folic acid supplementation in pregnant women , paid maternity leave ). Only 1/20 infrastructure support indicator ( access to nutrition information ) was rated as fully implemented by all experts. Barriers to implementing DDAs and infrastructure support included: legal feasibility or lack of regulations, inadequate monitoring/evaluation to ensure enforcement, commercial influences on policymakers, insufficient resources, shifting public health priorities with the COVID-19 pandemic and political instability. The experts prioritised 12 indicators across all five DDAs and eight infrastructure support indicators. Experts highlighted the need to improve implementation of all DDAs and identified ways to strengthen the enabling policy environment.