Direct laser deposition is a solid freeform fabrication process that is capable of producing fully dense components with full structural integrity. The process is greatly enhanced by the use of an omnidirectional coaxial powder nozzle, but in order to optimise the technique, accurate control of the operational parameters of material feed rate and incident laser power intensity is necessary. Both are affected by the axial powder stream concentration between the nozzle and the deposition point. In this investigation optical and image, analysis techniques are used to examine variations in the concentration over the full length of the axis. Based on this, a mathematical model relating directly to nozzle dimensions and material flow rates is developed and the results from it compared with the experimental findings. The two show good agreement.