Objectives/Hypothesis: Children with cleft lip and palate (CLP) often suffer from nasal obstruction that may be related to effects on nasal volume. The objective of this study was to compare side: side volume ratios and nasal volume in patients with unilateral (UCLP) and bilateral (BCLP) clefts with age-matched controls. Study Design: Retrospective case-control study using three-dimensional (3D) nasal airway reconstructions. Methods: We analyzed 20 subjects (age range = 7-12 years) with UCLP and BCLP from a regional craniofacial center who underwent cone beam computed tomography (CT) prior to alveolar grafting. Ten multislice CT images from age-matched controls were also analyzed. Mimics software (Materialise, Plymouth, MI) was used to create 3D reconstructions of the main nasal cavity and compute total and side-specific nasal volumes. Subjects imaged during active nasal cycling phases were excluded. Results: There was no statistically significant difference in affected: unaffected side volume ratios in UCLP (p =.48) or left:right ratios in BCLP (P =.25) when compared to left: right ratios in controls. Mean overall nasal volumes were 9,932 +/- 1,807, 7,097 +/- 2,596, and 6,715 +/- 2,115 mm(3) for control, UCLP, and BCLP patients, respectively, with statistically significant volume decreases for both UCLP and BCLP subjects from controls (P <.05). Conclusions: This is the first study to analyze total nasal volumes in BCLP patients. Overall nasal volume is compromised in UCLP and BCLP by approximately 30%. Additionally, our finding of no major difference in side: side ratios in UCLP and BCLP compared to controls conflicts with pre-existing literature, likely due to exclusion of actively cycling scans and our measurement of the functional nasal cavity.126 14751480National Institutes of Health/National Institute on Deafness and Other Communicative Disorders [T32DC005360]National Institutes of Health/National Heart, Lung, and Blood Institute [R01 HL105241]