We present two cases from a double-blind placebo-controlled study of diazepam in treatment of anxiety that illustrate the importance of attitudes of patients and physicians towards use of diazepam. Patient 1 exhibited symptoms of nausea, depression and increased anxiety, which both he and the research psychiatrist interpreted as a withdrawal reaction. Examination of the treatment code, however, revealed that the patient had been kept on the same dose of diazepam throughout this period and that he had maintained therapeutic plasma diazepam levels. This case illustrated a "pseudowithdrawal reaction" in a patient being maintained on active drug treatment. Patient 2 benefited remarkably from maintenance diazepam therapy and had manifested considerable anxiety during double-blind placebo substitution but his private physician expressed great reluctance to continue this treatment regimen because he had been influenced by unfavorable publicity. Further information on maintenance diazepam therapy and problems with withdrawal must be obtained under carefully controlled conditions.