This book is aimed for the people who may want to learn how to design a microcontroller based ECG device with graphical LCD (GLCD) output. The book describes the design, theory, development, and construction of the ECG unit in detail including a complete program listing. The highly popular PIC16F877 microcontroller has been taken and used as an example in the book, although most other types of microcontrollers could also have been used. Chapter 1 is an introduction to the ECG system in general where various ECG waveforms are presented and explained. The block diagram of the project designed in this book is also given in this Chapter. The ECG electrodes are described in Chapter 2. Chapter 3 is about the Data Acquisition Unit. Chapter 4 is about the Data Processing Unit. Chapter 5 describes details of the LCD used in the project. Chapter 6 and Chapter 7 are about the power supply and the construction of the project respectively. Chapter 8 is about details of the software developed for the project. Testing of the designed device is described in Chapter 10.