Some dozen mood measurement instruments are surveyed with an emphasis on multiplicity of mood measurement with applications reviewed under topic headings as follows : Mood scales, Group studies, Drugs and drug use, Alcohol and mood, Mood and smoking behaviour, Birth control and menstrual cycle, Mood and hypnotizability, Sleep and mood, Age, sex and mood, Mood and aesthetics, Mood state manipulation, Scale development and relationships, Recommendations. It is pointed out that any scale to be recommended to prospective users should (a) be relatively easy for self-administration, (b) have unambiguous scales, (c) be easy to score, (d) be quite short in administration time, (e) provide the maximum possible information.