A statistical work was performed to investigate effect of air jet texturing process parameters on acrylic filament yarn properties. It was shown that process parameters such as air pressure, overfeed and texturing speed significantly affect resultant yarn properties. Some structural changes were also observed by varying process parameters. Contrary to reported information in the literature, tenacity of air textured acrylic yarn increased by the increment of air pressure and it was found to be relevant with instability of the yarn. Overfeed and texturing speed had also significant effect as increase of both parameters resulted in lower yarn tenacity. Structural changes have also been observed especially with the change of air pressure and it was found that increase of air pressure up to some extent disturbed crystalline orientation of the yarn. According to statistical analysis and characterization methods, optimum parameters were determined as 300 m/min texturing speed, 5 bar air pressure and 5% overfeed for acrylic yarn used in this study.