Providers and patients are considering and pursuing PGD for ever-more conditions, but questions arise concerning how they make, view and experience these decisions, and what challenges they may face. Thirty-seven in-depth semi-structured interviews were conducted (with 27 IVF providers and 10 patients). Patients and providers struggled with challenges and dilemmas about whether to pursue PGD in specific cases, and how to decide. Respondents varied in how they viewed, experienced and made these choices, and for which conditions to pursue PGD (from lethal, childhood-onset conditions to milder, treatable, or adult-onset disorders). Several factors were involved, including differences in gene penetrance, predictability, and phenotypic expression, and disease severity, age of onset, treatability, stigma and degree of disability. Providers and patients face questions regarding possibilities of screening for more than one condition in one set of embryos, and limitations of PGD (e.g., inaccurate results). Characteristics of providers (e.g., amount of PGD experience, understandings of genetics, and use of genetic counselors), and of patients (e.g., related to broader moral and social attitudes) can also affect these decisions. These data, the first to examine several key questions concerning PGD, suggest that providers and patients confront several dilemmas. These findings have critical implications for future practice, guidelines, education and research.