In the heavily industrialized and densely populated Port of Rotterdam odour nuisance is the second largest reason for complaints. The DCMR EPA has a control room that is manned 24 hours, 7 days per week. It receives on a yearly basis about 5,000-6,000 odour complaints of residents. One of the tasks of DCMR EPA is to investigate the cause of odour nuisance by field inspection with the human nose. Comon Invent has developed an online E-nose technology. Various industries are using this technology to monitor odours emitted of their own operations. DCMR EPA and Comon Invent cooperate in a long-term program in the port of Rotterdam to explore the potential of this technology. The target is to establish a real-time monitoring system which provides situational awareness about odour and air safety related issues. The program involves networks of electronic noses in the port area and the neighbouring residential areas. The data gathered by the e-nose data is processed and related to other information sources. Among them are odour complaints of residents, field observations of DCMRinspectors and results of olfactometer laboratory testing. The olfactometry testing is performed in collaboration with VITO. This paper details some results of the program.