The aim of this study was to develop an instrument to measure the US public's attitudes toward people with epilepsy and to assess the initial reliability and validity of the instrument. A 46-item attitudinal instrument was developed and tested using a proportional, stratified, national, random-digit dial household telephone survey of adults aged > or = 18 (n=758). Exploratory factor analyses revealed four underlying constructs that accounted for 34.4% of the variance in the factor analysis: negative stereotypes (alpha=0.73); risk and safety concerns (alpha=0.85); work and role expectations (alpha=0.76); and personal fear and social avoidance (alpha=0.79). Knowledge was also assessed; participants with less knowledge about epilepsy had more negative attitudes. The results of these analyses provided evidence for reliability and construct validity of the instrument. Additional tests of the reliability, validity, and factor structure of the scales are necessary to refine the instrument.