The first monolithic photoreceiver integrating an HPT, two HBT's on a GaAs chip has been designed, fabricated and tested. A sensitivity of -30 dBM for 140 Mbit/s transmission rate was inferred from signal to noise ratio measurement. Taking into account the specific characteristics of high current gain-high speed heterojunction phototransistor, the receiver sensitivity has been analysed. For high current gain HPT's, the base layer is very thin and in this case, the early effect and the thermal noise of the base access resistance have to be taken into account. This leads to a trade-off between the base resistance and the current gain. Compared to PIN-FET receivers, the range of interest for HPT, from the point of view of sensitivity is located above a few hundreds Mbit/s, but for a monolithic photoreceiver implemented with HPT and heterojunction bipolar transisitors (HBT's) and advantages of monolithic integration leads to an extension of the application range.