OBJECTIVES: Little is known about the relative importance to patients and their willingness to accept tradeoffs among immunoglobulin (IG) treatment administration attributes. The objective of this study was to quantify patient and parent preferences for administration attributes of IG treatments. METHODS: United States adult patients and parents of children with a self-reported physician diagnosis of a primary immunodeficiency disorder completed a web-enabled, choice-format conjoint survey that presented a series of 12 choice questions, each including a pair of hypothetical IG-treatment profiles. Each profile was defined by mode, frequency, location, number of needle sticks, and duration. Before answering the choice questions, respondents were told to assume all treatments worked equally well. Choice questions were based on a D-efficient experimental design. Preference weights for attribute levels were estimated using random-parameters logit for each group. All respondents provided online informed consent.  RESULTS: A total of 252 patients and 66 parents completed the choice questions appropriately. Both groups prefered monthly to weekly,  home setting, shorter duration and fewer needle sticks of IG treatment relative to alternative choices (P <0.05).  Mode of administration was the least important attribute to both groups; however, parents strongly preferred self-administration to an appointment with a health care professional (P <0.05) whereas patients slightly preferred self-administration but were indifferent to the two modes.  Overall, 98% of parents and 84% of patients preferred therapy with options of monthly frequency, home setting, shorter duration, and fewer needle sticks.  CONCLUSIONS:  IG treatments that provide the option of a monthly frequency, home setting, shorter duration, and fewer needle sticks may address the needs of both patients and parents.