Although gender differences in a technological world are receiving significant research attention, much of the research and practice has aimed at how society and education can impact the successes and retention of female computer science professionals. The possibility of gender issues within software, however, has received almost no attention, nor has the population of female end users. However, there is relevant foundational research suggesting that gender-related factors within a software environment that supports end-user computing may have a strong impact on how effective male and female end users can be in that environment. Thus, in this article, we summarize theory-establishing results from other domains that point toward the formation of grounded hypotheses for studying gender differences in end-user computing. There has been much background research relevant to human issues of end-user computing, which we define here as problem-solving using computer software, also termed end-user programming in some of the literature (e.g., Blackwell, 2002; Green & Petre, 1996; Nardi, 1993). (See the glossary for definitions of these and related terms.) Despite this, few researchers have considered potential gender HCI issues and gender differences that may need to be accounted for in designing end-user computing environments. The most notable exception is Czerwinski’s pioneering research on the support of both genders in navigating through 3-D environments (Czerwinski, Tan, & Robertson, 2002; Tan, Czerwinski, & Robertson, 2003). Although individual differences, such as experience, cognitive style, and spatial ability, are likely to vary more than differences between gender groups, evidence from Czerwinski’s work as well as work in other domains, such as psychology and marketing, has found gender differences relevant to computer usage. In fact, some research has shown that some software is (unintentionally) designed for males (Huff, 2002). One reason gender HCI issues in end-user computing are important is that ignorance of gender issues has already proven to be dangerous: today’s low percentage of computer science females (Camp, 1997) has been directly attributed to the past unawareness of gender issues in computer science education and in the workforce. There is a risk that if gender HCI issues in end-user computing environments are ignored, a similar phenomenon could occur with female end users.