There are few explicit discussions in nursing literature of how qualitative research can be made as rigorous as it is relevant to the perspective and goals of nursing. Four factors complicate the debate about the scientific merits of qualitative research: the varieties of qualitative methods, the lack of clear boundaries between quantitative and qualitative research, the tendency to evaluate qualitative research against conventional scientific criteria of rigor, and the artistic features of qualitative inquiry. A framework for understanding the similarities and differences in research approaches and a summary of strategies to achieve rigor in qualitative research are presented.