We used a valid questionnaire to survey Iranian nurses' seeking information behavior and their confidence on different information sources. The frequently used sources were Internet" and “personal experiences” (54.8% and 48.2% respectively). “English medical journals” (61.9%) and “English textbooks” (41.3%) were the least frequently used sources. Nurses felt high confidence in sources such as “International instructions/guidelines” (58.6%) and “English medical textbooks” (50.4%). The main reasons for selecting sources were easy accessibility, being up to date and reliability. Google, Pubmed and Up to Date were the most used electronic sources. In addition, there were differences in terms of using some of these resources and nurse' age and gender. In developing information sources for nurses, factors such as reliability level, availability, and updatedness of resources should be more emphasized.