Of late the study of fixed point theory has increased to a great extent. Many online sites exists in fixed point theory. Fixed point theory has good applications in various fields like game theory, differential equations, operator theory and economics etc. The present work of our book is devoted to the study of common fixed point theorems for three, four and six mappings in metric and cone metric spaces. In the present work we obtain some common fixed point theorems in some recently defined in metric and cone metric spaces using different contractive conditions. The specialty of this book is that the theorems are proved without using the continuity of the maps involved. Thus it helps the researchers working in various fields.