Ti6Al4V alloys are considered difficult materials to machine, especially at high cutting speeds due to their low thermal conductivity and specific heat which causes high localized cutting temperatures at the tool-workpiece interface. For these reasons machining titanium alloys usually results in excessive tool wear and its low modulus promotes chatter. This regenerative vibration or chatter is a significant problem. In the investigation reported here, vibration monitoring has been used to optimise machining processes by correlating machining process parameters with vibration severity. Machining experiments were carried out under wet and dry machining conditions while vibrations were measured and analysed. The results have demonstrated that the application of a vibration monitoring system can be an important tool to increase machining speed.