Despite the growing evidence that the use of hand-held mobile phone while driving increases the risk of motor vehicle crashes and the banning by law, in many countries, of this kind of use, this behaviour is more and more spreading. Following a survey we have conducted in 2004, in 2005 we have realized in florentine area a monthly monitoring about this incorrect use of phoning while driving. Overall, 15001 vehicles were observed, and the prevalence of mobile phone use while driving was 2.6%, higher if compared with that referred to the previous year (1.8%). The association between mobile, hand-held, phone use and the considered variables (the same of the 2004 study) is always statistically significant and the conditions with the highest probability of meeting a phoning driver are showed by regression analysis. Intervention for reducing the spread of this behaviour is needed, especially if we consider the recent technological innovations introduced in the new models of mobile phones, which offer new distractions for drivers, the uncertainty of the absence of risk in using hand-free phone and the scarcely proved long-term effectiveness of legislation banning this use.