In real time it is difficult to access certain places by humans. So, it is better to use a robot that can be controlled from a remote location using voice commands. Our project is to develop a voice based system that works with respect to the commands given in Run time. We are developing a Robot that is controlled by voice commands. The words are recognized using MATLAB. The voice commands include forward, reverse, left turn, right turn etc. After recognizing the words the commands are transmitted to an 8051Microcontroller based system through RF module and RS232 interface. The 8051 is, respectively programmed to control the motor connected to the robot. This project involves both signal processing and communication. The word recognition part is implemented by extracting the formants feature of the speech signals and the values are listed in an excel sheet database. Then, k-Nearest neighbor algorithm based classifier is used to compare the run time input voice with the database. The classifier output gives the word to which the voice command corresponds .The serial communication part involves the transmitting of data with respect to the command detected through an RF module working at 434 MHZ frequency. The data received at the receiver side is decoded and an 8051 based system is used for controlling the motors of the robot.