Post-harvest spoilage of potato tubers results in approximately 9 million annual loss in the UK alone. In this paper, we report work completed with funding from the British Potato Council to develop an electronic sensor system (e-nose) to enable the early detection of spoilage diseases in stored potato tubers. The device is designed to detect the characteristic volatile organic compounds (VOCs) released during bacterial and fungal infections. Sensors were fabricated and tested for changes in their electrical resistance when exposed to the characteristic VOCs. For detecting bacterial soft rot caused by Erwinia carotovora in potato (cv. Maris Piper) tubers, metal oxide sensors were selected for incorporation into the prototype device. This is portable and can be used without computer control after threshold values and settling criteria have been downloaded. One tuber with soft rot in 100 kg of sound tubers could be detected in a simulated storage crate at 18°C. The device also detected an inoculated tuber within 10 kg of sound tubers, and followed the progression of disease in conditions typical of a commercial store (4°C, 85% relative humidity).