Many solid state fermentations have utilized fungi, bacteria and yeast in mixed culture. The finding and development of pencillin has opened the era for extensive use of liquid fermentatin using actinomycetes and fungi, subsequent negligence of research on solid state fermentation and mixed culture was noticed in the past. This paper reviews the kinds of solid state fermentation, products formed as well as merits and demerits of solid state fermentation. Products synthesized from old and new solid and submerged substrate fermentations are also given.