ABSTRACT Purpose: to describe the updating of the Observation of Communicative Behavior protocol in the age group from 0 to 72 months. Methods: the Observation of Communicative Behavior protocol was revised and updated, with the insertion of the child development milestones in its various areas, becoming a child development screening tool. Results: the protocol includes 188 items, distributed in 10 age groups from zero to 72 months. The items were organized as follows: from zero to 24 months, divided by quarter (four age groups); from 24 to 36 months per semester (two age groups); and from 36 to 72 months, divided by year (four age groups). The items covered the areas of child development and its main milestones. The score is registered in the protocol and a score of 0 - does not perform the action or behavior, 1 - performs the action in an atypical, restricted manner or it is being acquired, 2 - properly performs the action/behavior, is attributed to the response, after analysis. Few materials and a structured environment are needed to apply the protocol. Conclusion: the updating of the Observation of Communicative Behavior protocol has a direct impact on the initial assessment of children with or without suspected delay in child development and should be used by health professionals in monitoring typical child development (routine) or in cases where the child receives specific stimulation.