The prevalence of iron deficiency anaemia was investigated among 1,210 school girls in Riyadh, Saudi Arabia. Anthropometric measurements were recorded. A dietary and socio-economic status questionnaire was administered and heamoglobin (Hb), serum iron and ferritin were estimated. Wasting and stunting is common among the 7- and 14-year-old girls. A total of 8.5% of children showed Hb level below 10 g/dL while 55.4% showed Hb level below 12 g/dL. It was found that 26.3% of the girls have serum iron below 10 mumol/dL while 16.1% of subsample of the girls showed serum ferritin level of less than 12 micrograms/dL. The most affected ones are those in the age group of 7-14 years old. The dietary questionnaire revealed that 16.5% of the girls did not take breakfast at home and depend on snacks offered in the school canteen which consist mostly of biscuits, chocolate bars, potato chips and carbonated cola drinks. No association between education of mother and father and breakfast consumption at home was detected. Tea drinking is common among these girls while fresh fruits and vegetable consumption is infrequent. Iron deficiency anaemia is highly prevalent among these schoolgirls which seriously affects the growth of 7- and 14-year-old girls. An in-depth investigation of the etiological factors of iron deficiency is urgently needed and meanwhile a suitable iron supplementation program is recommended.