This proof-of-concept study demonstrates that sinonasal microbiome sequencing with suctioned nasal secretions in children is technically feasible. Eighteen children were enrolled: 11 with symptoms of rhinosinusitis and 7 controls. Samples were collected via a sterile flexible respiratory suction catheter into a suction trap. Samples were analyzed with 16S ribosomal RNA sequencing and subsequent phylogenic mapping. The log2-fold differential abundance in class demonstrated significantly higher quantities of bacteria from the classes Negativicutes, Bacilli, Mollicutes, and Alphaproteobacteria as compared with controls, with a false discovery rate-corrected P value <.01 for all 4. The experimental group showed a higher range of alpha diversity than the control group, although none of the measures of alpha diversity showed a statistically significant difference. Overall our study demonstrates that sinonasal microbiome sequencing with suctioned nasal secretions is a readily available and technically feasible alternative for study of the pediatric sinonasal microbiome.