A Diploma Thesis titled “Correlation of driver behaviour and fuel consumption using data from smartphones” was recently presented by Eva Michelaraki. The aim of this Diploma Thesis is the correlation of driver behaviour and fuel consumption using data from smartphones. To achieve this objective, data collected from 17 drivers who participated at a naturalistic driving experiment for four months are analyzed. The results demonstrated that there was a remarkable reduction in fuel consumption, by improving the way participants were driving and also a smoother and a greener driver behavior was achieved. A stronger correlation has emerged between harsh accelerations and fuel consumption, but also speed, braking, smartphone usage while driving, driving at night and demographic features had a direct impact on fuel consumption.