This paper presents a review of the phenomenology and psychodynamics of affects in borderline patients. The first part demonstrates that in most current conceptions of the borderline disorder affective disturbances are regarded as to be characteristic. In this context, the strong overlap between borderline disorders and affective disorders found in many empirical studies is described and different hypotheses are presented to explain this phenomenon. The second part of this review is concerned with the psychodynamics of affects in borderline patients. The role of affects in thinking, behaviour, self perception and the regulation of object relations is discussed. Borderline and other severe personality disorders are assessed from the perspective of affective disturbances. The psychodynamic functions of particularly characteristic affects such as anger, anxiety, depression and boredom are discussed. The close connection between affective and cognitive functioning in borderline patients is described and evaluated with regard to modern theories of affect and cognition. Finally, the role of affects in the treatment of borderline patients is discussed.