The aim of the work reported in this paper has been to assess whether or not it is possible to improve the mechanical properties of powder HIPped Ti6Al4V by optimising HIP parameters and by post-HIP heat treatments. Two approaches have been used. The first is to vary the cooling rate from the standard slow cooling in the HIP of about 5ºC/min to 50ºC/min by using jet cooling. In the second samples have been post-HIP heat treated at the HIP temperature of 930°C and at temperatures just below the beta transus and cooled at rates of about 180ºC/min. This approach is aimed at using the partitioning of oxygen and the reduced fraction of alpha near the transus to strengthen the alpha in the transformed beta which is formed when samples are cooled rapidly. Changes in microstructure microhardness and fatigue properties are reported as a function of these heat treatments.