OBJECTIVEto validate the content of an instrument for documenting the steps of the Nursing Process, using the standardized languages NANDA-I, NOC, and NIC (NNN), aiming at hospitalized patients in an Intensive Care Unit (ICU).METHODA methodological research performed in three steps: design of the existing instrument from the systems NANDA-I, NOC and NIC; content validation by 13 judges, from a four-point Likert-type scale - items were evaluated as to their clarity and pertinence; applicability: judgement of the content regarding clarity, reading ease, and presentation for 40 critical-care nurses. The Content Validity Index (CVI) and the Kappa coefficient (k) was calculated to measure the proportion of relevance and clarity, was well as to verify the level of agreement between the experts in each item.RESULTSThe instrument was considered clear and pertinent, with CVI above 0.8 in most items and overall Concordance Index (CI) of 0.90, showing a satisfactory level of agreement between judges. Regarding applicability, the instrument was deliberated clear, of easy reading, and with proper presentation by most critical-care nurses, being validated through 11 diagnoses with their respective results and nursing interventions.CONCLUSIONThe instrument showed to be valid and applicable for the group studied. It is expected that this study is able to contribute to the improvement of the Nursing Process in intensive care.