Vast consumption of natural resources threats the human life. Growing scarcity of fresh water is posing a great challenge to humanity as well. Thus many governments take special measures for efficient use of freshwater. There are many products that use too much fresh water. Toilet is among these products. In search of new solutions for lack of fresh water, designers design alternative toilets. However, it is necessary to understand the evolution of toilets and current state to develop better new technologies and products. This thesis investigates the evolution of toilet design throughout the history. Factors affect toilet design, and changes in their improvement throughout the evolution of toilets are examined. The study also aims to investigate advantages and disadvantages of squat and flushed toilets and their current state.