Introduction: Documentation of nursing care and procedures is an evidence of performance and quality of these cares. Failure to document could be a sign of inadequate care performance.

Method and Materials: This study was carried out to determine causes of inadequate nursing documentation in wards of Shahid Beheshti Hospital, Zanjan, in 2003. This study was a descriptive survey; a checklist was designed according to standard principles of nursing documentation which was validated by 10 academic members. Patients' files were assessed based on this checklist. Also, 20 nurses were interviewed (open question) to determine of causes of incorrect nursing documentation.

Results: The results showed that 17% of items of checklist had been documented correctly, documentation’s of 35.81% of these items were incomplete and 48% of items had not been documented. The interviews showed that the inadequate nursing documentation was related to inattention to these documentation’s and lack of control of nursing documentation, work overload of nurses, educational problems and unawareness of legal and occupational issues.

Conclusion: Documentation of nursing care was inadequate. The most important causes were inattention and lack of control. Considering importance of nursing documentation, ways to solve these problems must be sought.