Objectives: Psychological research of infertility has been hampered by the lack of infertility specific measures. This study was conducted to develop a brief instrument to measure different aspects of infertility related stress.Design: A self-report questionnaire, was administered to 2302 men and women consecutively referred for treatment through In Vitro Fertilization, Intrauterine Insemination or Therapeutic Donor Insemination.Materials and Methods: A preliminary 84 item questionnaire with 7 provisional subscales was developed by culling the scientific and popular infertility literature for problematic beliefs and situations reported by patients or clinicians. Respondents indicated degree of agreement with each item on a 6 point Likert scale (e.g. I dread family get-togethers ). Couples also completed the Beck Depression Inventory, State Anxiety Scale and Social Desirability scale of the Jackson PRFE. The final 46 item questionnaire was derived through a sequential process of item analysis. First, items were chosen to maximize subscale reliabilities. Next, items substantially correlated with other subscales or a measure of social desirability were eliminated.Results: As a total score, the IPI had high internal consistency (coefficient alpha = 0.93). Five subscales had good to excellent reliability: Social Stress (0.87), Sexual Stress (0.77), Relationship Concern (0.82), Future Concern (0.80), Role Identification (0.84). The mean intercorrelation between subscales was 0.44. Women scored higher than men on all scales indicating greater specific and total stress. Among women, Social Stress and Relationship Concern scores fluctuated in a non linear fashion as infertility duration increased, whereas men's scores on the same subscales increased linearly over time. Both men and women experiencing male factor infertility reported greater social and sexual stress than men and women experiencing female factor infertility. All 6 scales had significant but moderate correlations with measures of anxiety (mean = 0.30) and depression (mean = 0.38). However 3 subscales; Social Stress, Sexual Stress and Relationship Concerns appeared to be the best predictors of emotional distress for both men and women.Conclusions: The IPI is a reliable instrument that measures distinct dimensions of infertility stress. It appears sensitive to differences in gender, diagnosis and duration of infertility. Correlations between subscale scores and other clinical measures gave evidence of convergent validity. Subscale scores also appear to have clinical utility in terms of delineating more specifically the nature of infertility stress.