The political science discipline has recently engaged in contentious debate about the value of “research transparency,” particularly for research with human participants. The discipline is also holding vital conversations about research ethics and is rekindling dialogue about different ways of knowing. We offer an integrated account of how the actions that scholars who conduct human participant research take to respect ethical principles (which vary by research substance and settings), and their epistemological commitments (which vary across researchers), influence openness, a broader concept than “transparency.” These principles and commitments shape scholars’ openness practices simultaneously—both independently and in concert—serving as a prism through which multiple features of a research project are refracted, and resulting in a scholar’s inclination and ability to pursue openness in different ways and to different degrees with the audiences of her work. We also show how ethical principles and epistemological commitments can not only constrain and prevent openness, but also animate and require it. We suggest that scholars pursuing openness ethically, and in ways that honor their epistemological commitments, represents good social science, and we offer strategies for doing so. To develop our argument, we focus primarily on two research methods, ethnography and interviews, and on openness toward two audiences, human participants and research communities. Our account illuminates how the heterogeneity of human participant research makes it inappropriate, indeed impossible, to develop blanket rules for pursuing openness. Throughout, we highlight the importance of reflexivity for the ethical conduct of, and for being ethically open about, political science research.