The study identified priorities of the Patient Assessment Data (PAD) using the Japanese Psychiatric Nursing Assessment Classification System (PsyNACS©) derived from 644 psychiatric nurses’ responses who were practicing in specific units: Acute Care Units (ACU), General Care Units (GCU), Long-term Care Units (LCU), physically Complicated Disease Care Units (CDCU), and Dementia Care Units (DCU). Secondary analysis of the PsyNACS© on-line survey data using four levels of “importance” was used to determine the priorities: 1) unnecessary; 2) quite important; 3) important and 4) very important. The Mean Factor Points (MFP) and the Welch’s ANOVA were calculated. PsyNACS© score of 3 or higher indicates the PAD as priority. The results showed that in the ACU PAD1, “Psychological symptom”, “Stress coping”, and “Mood disorder and aggression”, and PAD2 “Information of adherence”, and “Information of the psychiatry rehabilitation”, and PAD7 “Situation of the family and social life”, “Relationship to the health care providers”, and “Relationships with others” are high priority (high importance). Other PADs showed results below PsyNACS© score of 3. The GCU had PAD 3 “Balance of water”, the LCU had PAD 4 “Intention/Point of view”, and “Thoughts of the patient” and PAD 7 “Disease and family”. The CDCU showed PAD 2 “Blood test”, PAD 3 “Excretion situation”, and PAD 5 “General health condition”, “Respiratory and chest sympCorresponding author.