There were several errors in the article by Aceijas C, Friedman, SR, Cooper HLF, et al. Estimates of injecting drug users at the national and local level in developing and transitional countries, and gender and age distribution. Sex Transm Infect 2006;82(Suppl III):iii10–iii17.

In the abstract (lines 17–18), the sentence “Greater dispersion of national IDU prevalence was observed in Eastern Europe and Central Asia, and Asia & Pacific (IQR 1.91 and 1.47 respectively” should have been deleted. The last sentence of the results section (“Greater dispersion…Caribbean”) should also have been deleted.

Also in the abstract, the values of Q1 and Q3 for Eastern Europe and Central Asia are incorrect. They should have been as follows: Q1 0.39%; Q3 1.32%. The values of Q1 and Q3 for Asia and the Pacific should have been: Q1 0.14% and Q3 1.47%. The values of Q1 and Q3 for the Middle East and Africa should have been: Q1 0.11%; Q3 0.23%, and the values of the median and maximum Q1 and Q3 in Latin America and the Caribbean should have been 0.11%, 0.69%, 0.04% and 0.13%, respectively.

In the results section, the values of Q1 and Q3 for Eastern Europe and Central Asia are incorrect and should have been <0.39% and 1.32%. The values of Q1 and Q3 for Asia and the Pacific should have been ⩽0.14% and <1.47%. The values of Q1 and Q3 for the Middle East and Africa should have been 0.11% and ⩽0.23%, and the values of the median, maximum, Q1 and Q3 in Latin America and the Caribbean should have been ⩽0.11%, 0.69%, ⩽0.04% and ⩽0.13%, respectively.