Gait is a complex sequence of movements so that it is very hard to analyze in clinic. Children with cerebral palsy have lots of different type of gait abnormalities. There is no clinically satisfied and reliable gait assessment tool for analyzing gait problem in cerebral palsy. The purpose of the review was to determine the reliability of clinically available video based observational gait analysis on children with spastic hemiplegics and diplegics and to investigate how they can be used in clinical practice as a standard examination tool. The review results showed that clinically available methods have moderate level reliability for between rater reliability and moderate to advance level reliability for within rater reliability. This review suggested that between rater reliability is high enough to use it in clinical practice but within rater reliability needs to be improved by the feature studies.