Summary. A survey of G6PD deficiency in Malta including 1145 males and 369 females has shown that 2.7% of the males and 1.9% of the females have enzyme deficiency. More than 60% of the enzyme‐deficient males but none of the females had decolorization times between 90 min and 24 hr. Using quantitative estimation of Hb A2 as a measure of β‐thalassaemia, an incidence of 3.4–3.6% was found. A raised Hb F was found in 2.3% of cases. The incidence of G6PD deficiency and thalassaemia does not seem to be correlated with intermarriage.