Understanding the utilization pattern of infertility health and medical services can assist health system managers in providing better and more efficient care to affected population. This study aims to investigate the patterns in the utilization of infertility services in Iran.We performed a survey of 10 783 women in 28 provinces from 2004 to 2005. We used a systematic sampling method to draw a total of 400 clusters, the probability for selection being proportional to the size of the urban and rural population in each province. The categorization of the woman as "presumed infertile" was based on her own report of infertility at some time during her married life. We also studied the measures taken for the latest episode of presumed infertility. For each of these measures, we recorded the reason(s), the year in which it was taken, and the time interval separating it from contraceptive discontinuation. Data analysis, using the software package STATA 8.0, included descriptive statistics and computation of 95% confidence intervals (CI) as well as chi(2) and logistic regression procedures adapted to the complex sampling design.A total of 1592 women had presumed infertility at some period after their marriage (14.8%, CI0.95 = 13.8-15.7%), and 1291 subjects had taken measures to deal with the problem (81.1%, CI0.95 = 78.7-83.5%). These rates did not show any significant differences between urban and rural women (p > 0.05). In 70% of these cases, the first measure was a visit to a specialist physician and in 70% the woman had sought care in the private sector. Visits to specialists and private health care facilities had increased over the last three decades, with fewer visits to general practitioners (GPs) and midwives and less use of self-medication or traditional/local therapies. The most common motive for those who had not taken any treatment was their unwillingness to have their problem known and discussed by others (29.3%). The determinants of treatment-seeking behavior were current primary infertility (OR = 4.15, CI0.95 = 2.53-6.80), higher education (OR = 1.39, CI0.95 = 1.04-1.86) and living with husband (OR = 1.83, CI0.95 = 1.01-3.32).The current study is the first attempt to present a population-based pattern of service utilization by infertile women in Iran. It shows that for these patients, the first contact with the health system takes the form of a visit to a specialist physician, and is more likely to involve the private sector.