Thalassemia is the most common monogenic inherited disease worldwide and it affects most countries to various extents. This review summarizes the current approaches to phenotypic and genotypic diagnosis of thalassemia in clinical practice. Prevention strategies that encompass carrier screening, genetic counseling and prenatal diagnosis are discussed. The importance of public education and an awareness of a changing perception regarding this group of diseases are emphasized. It also addresses the impact of the rapidly increasing knowledge in disease severity modification by hemoglobin F (Hb F).