The importance of candidate software requirements can vary by orders of magnitude, yet most software providers do not have accurate and efficient means for selecting among them. This papers describes a case study at Ericsson Radio Systems AB of two techniques for software requirements prioritizing as a means for determining the importance of candidate requirements, a pair-wise comparison technique and a numeral assignment technique. The results from the case study indicate that the pair-wise comparison technique is an efficient, informative and accurate means for finding the candidate requirements importance. We therefore recommend the pair-wise comparison technique for software requirements prioritizing. At Ericsson we have extended its use in other development projects.