Despite graduating from top law schools and getting hired as associates at competitive law firms at the same rate as men, women are still disproportionately underrepresented in partnership positions in Big Law. This paper investigates supply-side and demand-side explanations for this phenomenon. Through interview-based research and a survey of 437 attorneys, I identify the major contributing factors to this persistent gender gap. My research shows that while women are taking on more at home with regard to childcare and housework than their male colleagues, they are not significantly more interested than men in leaving large law firms despite extant scholarship’s focus on attrition. Instead, my findings provoke two alternative explanations for the gender gap: First, implicit bias makes it more difficult for women to network with predominantly male clients in an increasingly competitive legal environment that emphasizes client generation and retention. Thus, interpersonal dynamics inhibit their ability to bring in business, and in turn, push them off the partnership latter. Second, female associates identify finding a mentor as a key problem they have encountered. Meanwhile, senior women do not recognize a lack of mentorship as a major obstacle they have faced. This disconnect in experiences between entry-level and senior-level attorneys suggests that young women are struggling to find mentors amongst experienced attorneys who do not realize the importance of having one.