The micromilling process is used to create complex features in a wide range of engineering materials. However, for difficult-to-cut materials like Ti-alloys, limited stiffness of the micro-tool is a major obstacle. To counter low stiffness, high rotational speeds can be used to reduce the chip loads and, therefore, the cutting forces. The high spindle speeds and low tool stiffness make the process susceptible to instability due to dynamic variation in the forces. The low thermal conductivity of Ti-alloys can increase the cutting zone temperature, leading to a variation in the cutting force and, hence, dynamic instability. The presence of cutting fluid can reduce the friction and dissipate the heat generated. The effect of lubrication on the cutting forces and chatter in the high-speed micromilling of Ti–6Al–4V has been investigated in this paper. Experiments were carried out at different spindle speeds and feeds in both dry and lubricated conditions. The study revealed that three distinct operational regimes exist in high-speed micromilling: lubrication sensitive, insensitive and the transition regimes. The range of spindle speeds corresponding to the transition regime lies between 40,000 and 60,000 rpm. A significant reduction of ∼38% in the cutting forces with lubrication has been observed in the lubrication sensitive regime. Velocity-chip load dependent coefficients have been used to capture the process mechanics. Note that a two degrees-of-freedom stability model with the velocity-chip load dependent coefficients yields a transcendental equation which does not have a closed-form solution. Hence, a novel numerical scheme based on the Newton–Raphson method has been developed to determine the stability limits. The predicted stability limits show a substantial increase (up to 47%) in the stability limits in the lubrication sensitive regime. The predicted stability limits are in reasonable agreement with experimental limits determined via frequency spectrums of acceleration and surface topography.