The present study evaluated the efficacy of a four-week seminar which emphasized the principles of Agentive Theory. This theory, which is compatible with theories of a phenomenological/ existential perspective, was first developed by C. T. Warner, an American philosopher. Agentive Theorists/Therapists emphasize that our negative emotions, ie., depression, anger, etc. , are assertions or judgments we make and not merely feelings we are responsible for controlling or expressing. Forty-eight outpatients who sought help with personal/emotional problems from a department of behavioral medicine were assigned to either a treatment or waiting-list control Group. Following a four-week treatment phase, the treatment group was shown to have made significantly greater improvement than the waiting-list control group with respect to general mental health, somatization, depression, anxiety, hostility, phobic anxiety, psychoticism, anger, and guilt.