Nasal obstruction is frequently reported by patients with sleep apnea and complicates the choice of a nasal or oronasal mask for continuous positive airway pressure (CPAP) therapy. However, the type of interface used for the delivery of CPAP is crucial to ensure tolerance and compliance. The aim of this prospective pilot study was to identify whether the validated Nasal Obstruction Symptom Evaluation (NOSE) score rated at CPAP initiation was associated with the type of mask used after 4 months of treatment. Patients completed the NOSE questionnaire before initiation with automatic CPAP. The mask used (nasal/oronasal) after 4 months was documented. In total, 198 consecutive patients with sleep apnea were included. NOSE score (>50/100) was independently associated with the use of an oronasal mask at 4 months (sensitivity, 34.8%; specificity, 87.5%). The NOSE questionnaire could be a simple decision-making tool to guide the choice of mask during CPAP initiation.