Driving a vehicle with inadequate tire pressure can generate more ground friction, causing an increase in fuel consumption and, therefore in CO 2 emissions. Another consequence is uneven tread wear, affecting braking distance and vehicle control. This paper presents the implementation of a Tire-Pressure Monitoring System (TPMS), which is a system that alerts the driver of a vehicle about a tire pressure change. For this, four prototypes were designed to monitor and transmit the tire pressure and temperature of a vehicle. For the transmitter circuits design, ATmega328 microcontrollers, NRF24L01 transceiver modules, Honeywell NBP series pressure sensors and LM35 temperature sensors were used. In addition, a receiver that incorporates an NRF24L01 module to receive the signals coming from the transmitters was developed. The received data are sent via Bluetooth, with the HC-05 module, to an Android application developed in App Inventor, which is an open-source web application. To install the circuits on the tires, compact cases were designed in Solidwork, which were printed using the Prusa i3 3D printer. The results obtained demonstrate the effectiveness of the monitoring system and the accuracy of the measured data, as well as the relevance of the Android application to alert the driver in a simple way about any pressure change in the tires. These results suggest the possibility of using the prototype developed in realistic scenarios to monitor tire pressure in vehicles without this technology.