Malnutrition in infants under six months of age (u6m) is poorly identified and managed in many countries, increasing these children’s risk of poor growth and development and preventable mortality and morbidity. New 2023 WHO malnutrition guidelines recommend assessment, classification and treatment at primary health care level. This study aimed to assess primary health facility availability and readiness for WHO-recommended nutritional care in infants u6m. We adapted the WHO Harmonized Health Facility Assessment (HHFA) with additional items for Management of small and nutritionally At-risk Infants u6m and their Mothers (MAMI): the HHFA-MAMI tool. Methods included survey of health care providers, direct observation and data extraction from routine registers to calculate mean percentages of a set of items for different readiness areas. We assessed 15 primary health facilities in Senegal, focusing on the five contact points for infants u6m: delivery and postnatal care, immunization programmes, sick child clinics and community health care. The HHFA-MAMI scores with interquartile range (n=15) were: general service availability 51% (35-63), general service readiness 69% (64-76), management & finance 50% (44-59), clinical quality of care 48%. MAMI availability scored 50% and readiness 36%, MAMI infrastructure scored 72%, health workforce 61%, assess MAMI 53%, classify MAMI 17% and treat MAMI 38%, equipment 32% and guidelines & training 23%. Service utilization was highest in postnatal care and immunization contact points, MAMI availability & readiness was highest in delivery and postnatal care. We conclude that primary health facilities in Senegal have potential to care for infants u6m at risk of poor growth and development with high general PHC readiness and frequent use of care contact points for infants u6m. MAMI availability and readiness require improvements to provide WHO-recommended care.