CONTEXT: It is useful to periodically update the estimate of the unmet need for contraception in the developing world and other regions of interest. National surveys since 1990 permit the calculation of estimates based on the standard definition used in the Demographic and Health Survey series, as well as alternative definitions. METHODS: Fifty-five national surveys are used to estimate numbers and proportions of women with unmet need, according to marital status, spacing and limiting purposes, age and region. RESULTS: In the developing world, an estimated 105.2 million married women have an unmet need. Unmarried women add 8.4 million, and the former Soviet republics add 9.1 million (of all marital statuses), for a total of 122.7 million. The proportion of married women in the developing world with an unmet need is 17%, lower than previously estimated because of a declining trend in many countries that reflects growing contraceptive use. For unmarried women, the proportion is 3%. Women aged 15–24 account for one-third of unmet need. Many women classified as having unmet need do not plan to use a method, but they are generally offset by women who want a child within two years yet still plan to use. CONCLUSIONS: The unmet need numbers reflect the upward pressures of population growth acting against the downward push of declining proportions with unmet need. The total estimate of 122.7 million women with unmet need represents a substantial and continuing challenge for agencies and governments concerned with ensuring access to contraceptives.