A new pressure sensor based on the use of a light dependent resistor (LDR) is introduced in this article; the sensor being called photo-conductive light pressure (PLP) sensor. The sensor uses a mechanical system to transmit pressure from the fluid system to a filter pin, causing it to move. The displacements of the filter pin due to the applied pressure allow different amounts of light, sent out by a light emitting diode (LED), to reach a light dependent resistor (LDR). By direct calibration, the resistance changes are converted into electrical voltage and thus real pressure value. The proposed sensor is found to be simple to use and reliable, low in cost and is recommended suitable for pressure measurements of highly viscous fluid systems. The sensor proposed in this work gives a maximum pressure range of 100bar and shows high repeatability and accuracy in the obtained results with a sensitivity, a sensitivity error and a response time of 6.62mV/bar, 0.15% FS and 1.66s FS, respectively.