Ultrasound is widely used in medical imaging. Unfortunately, speckle noise decreases the quality of the ultrasound image. One of the filters to reduce speckle noise in ultrasound image is the median filter. The median filter has no complex algorithms and there is no need for long time implementation of the median filter. Especially, for the portable ultrasound machines, the median filter is an important filter to reduce speckle noise. In this paper, we analyzed the effect of the median filter for ultrasonic imaging. To carry out our study we selected a kidney image simulated by the Field II program and a cameraman image from MATLAB. For the portable ultrasound machines, the performance of the median filter with the different window sizes is evaluated with the image quality metric and qualitative comparison.