A review of the literature on the ductile fracture of metals and alloys reveals almost immediately that the majority of investigations approach the topic from a fracture mechanics point of view and that papers based entirely on microstructural research are rare. In a substantial number of papers the two viewpoints are combined. Correspondingly, Section 2 covers some aspects of continuum theory which would be of value in regard to this review and also includes a few points on the other extreme, namely the atomic approach to fracture. The microstructural regime covers the broad area between these two concepts. Since ductile fracture depends on the history of plastic deformation in the specimen, an outline of a successful theory of work hardening has been included. Also, it should not be overlooked that the experimental tools for microstructural investigations developed rapidly during the past decade and are briefly reviewed in Section 2.4. Section 3 addresses rupture since this mechanism includes the fundamental processes which govern ductile fracture generally and in particular the final separation. The most common mode, fibrous fracture, is reviewed in Section 4. Continuum mechanics still plays the major role in fibrous fracture research, although microstructural considerations are becoming a greater part of this work. In the final section a variety of topics which have a bearing on a more comprehensive understanding of ductile fracture (such as delamination and cleavage fractures, the role of voids in microcrack initiation, the energy of dislocation cell walls, and the thickness of microtensile specimens and the rate of straining for in situ experiments) are emphasized and discussed critically. A brief perspective summary pointing out the significant role of rupture processes which also govern the final separation of fibrous fracture concludes Section 5.