As pharmaceutical industries now a days concerns with the safety and continuously enhance the quality of the drug products. The development of pharmaceutical industries is based on the innovation of the product as well as the manufacturing process by keeping quality in the mind. In earlier times, the development of pharmaceutical products shows the failure in the quality and hence alters the therapeutic effect of the product. Quality by test (QbT) was the only way to maintain the quality of the drug product before the FDA launches the current Good Manufacturing Practices (cGMP), which was an approach without understanding the processes. So FDA decided to applied the several Design of Experiments (DoE) in the pharmaceutical fields. QbD (Quality by design) was one of the design experiment approved by the FDA to maintain the quality of the drug products before reaching to the market. In pharmaceutical industry, QbD brings cost-efficiency and simplicity of manufacturing process into reality. QbD is a systematic risk-based, proactive approach to pharmaceutical development that begins with predefined objectives and emphasizes product and process understanding and process control based on sound science and quality risk management. The main aim of this review is to discuss the concept of pharmaceutical Quality by Design and describe how it can be helpful to ensure pharmaceutical quality & drug development.