Introduction & Objective: Documentation is one of vital and important aspect of nursing tasks. Nurse's documentation must be complete, accurate and timely. Incomplete documentation can lead to negative outcomes in treatment and lack of treatment.

Goal of this study was assessment of documentation of information by nursing staff inpatient's files.

Materials & Methods: This research was a descriptive study that was done on 150 inpatient's files in medical educational centers in Ardebil. Instrument of data collection was checklist that designed, for research objectives.

Data were analyzed by SPSS program and results showed in statistical descriptive tables.

Results: There were not composite graphic charts 100% in the studied files. Seven forms from eight forms that must completed by nurse were standard. Average documentation nursing were in the admission and discharge summary sheet 25%, in the pre – operation care sheet for ward nurse 48% and for operation room nurse 9%. In the operation report sheet 69.3%. In the recovery room record for entrance items and Exit items 16.2% and 62% respectively. In the nurses note sheet rate of records was 96.3%, and in the vital signs control sheet 83.3%.  Total average documentation nursing was 51.2%.

Conclusion: This study showed that half of data documented by nursing staff. Seems lack of knowledges regard to items that must be documented by nurse in inpatient's files, being careless regard to importance of documentation, insufficiency of nursing and medical records management and defect in designing of forms could be influence factors on this condition.