Malnutrition is one of the most prevalent Public Health Problems in Pakistan. It is one of the major underlying factor for high Infant and Under 5 Mortality rate in Pakistan. Poverty, lack of Education, Poor environmental hygiene and food fads are some of the reasons for its high prevalence in Pakistan. In this lecture, I have tried to explain, what is the magnitude of Malnutrition in Pakistani Society, its causes, types, diagnosis, and treatment.