In clinical practice and diagnostic guidelines, a distinction is made between trauma after single and repetitive negative events (complex trauma). While post-traumatic embitterment disorder (PTED) is defined as a reaction to a specific elicitor, an open question is whether there is also complex embitterment. A convenience sample of 118 psychotherapy outpatients was asked to answer the PTED Scale, the General Health Questionnaire, the Personality Style Inventory, an aggressiveness scale, the Beck Depression Inventory, and whether feelings of embitterment were caused by a single or multiple events. A non-elevated PTED Scale score of <1.5 was found in 31.4%, an elevated score of ≥1.5 and <2.5 in 50%, and a clinically relevant score of ≥2.5 in 18.6% of psychotherapy patients. When examining patients with an elevated score, a single elicitor was reported by 24.7% and multiple stressors by 75.3%. Embitterment was prevalent in psychotherapy patients, with approximately two-thirds showing elevated and nearly one-fifth showing clinically relevant severity. Patients more frequently attributed their embitterment to multiple events than to a single event.