To design and validate a hearing-related quality-of-life questionnaire targeted toward parents and deaf or hard-of-hearing infants and toddlers: the Hearing-Related Infant/Toddler and Parent Quality of Life (HIP-QL) questionnaire. Cross-sectional questionnaire and prospective instrument validation. Academic pediatric otolaryngology clinic. A 67-question questionnaire developed from constructs of a grounded theory analysis was administered to parents of 31 deaf or hard-of-hearing children and 14 typically hearing children. Questionnaire construct validity, reliability, and discriminant validity were tested. Based on exploratory factor analysis, a 32-item construct composed of developmentally appropriate questions was reduced to a 17-item construct with 4 domains addressing quality of life for both child (auditory/communication behavior, temperament) and parent (management, parent-directed factors). Internal consistency measures were appropriate (Cronbach's alpha = 0.65), and test-retest reliability was high (intraclass correlation coefficient = 0.73). Total HIP-QL scores correlated significantly with related total PedsQL scores (r = 0.57, P < .001). As predicted, parents of children who are deaf or hard of hearing reported significantly lower mean HIP-QL scores but not mean PedsQL scores. HIP-QL was more sensitive than PedsQL for predicting case versus control membership (86.7% vs 76.9%). Multivariable regression confirmed a negative relationship between severity of hearing loss and HIP-QL score after controlling for age, sex, income, and maternal education. This context-specific questionnaire is the first validated quality-of-life instrument for parents and deaf or hard-of-hearing infants and toddlers. Previously, parental stress and functional disability questionnaires were used as proxies; therefore, this questionnaire has the potential to serve as an important tool for patient- and caregiver-centered outcomes research.