Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) has a triad of symptoms: nasal polyposis, asthma, and NSAID hypersensitivity. Little is known about symptom timing and disease progression. The aim of this study is to characterize disease progression in N-ERD. Patients with N-ERD were prospectively interviewed and classified into 4 groups based on their first symptom at initial N-ERD onset (asthma, nasal polyps, NSAID hypersensitivity, or all concurrently). Associations of patient characteristics with the 4 groups were examined, along with associations within the "asthma first" group. Patients (N= 240) were mostly female (68%) and self-identified as non-White (77%). Half (N= 119) reported asthma as the earliest symptom in the N-ERD triad. Compared with other groups, "asthma first" was associated with younger age of onset (25 years, standard error ±1.3, P < .001) and higher body mass index (BMI) (odds ratio [OR]= 1.3, 95% confidence interval [CI]: 1.06-1.7, P= .02). In this group, age of onset <20 years was associated with female sex, Latino ethnicity, and higher BMI (all P < .05). The "NSAID sensitivity first" group was significantly associated with male sex (OR= 3.3, 95% CI: 1.5-7.4, P= .004) and pollution exposure (OR= 4.4, 95% CI: 1.6-11.9, P= .003). At the initial presentation, 27% of patients were unaware of their N-ERD diagnosis. Black and Latino patients were more likely to be unaware of their N-ERD diagnosis compared with White (P= .003). The median diagnostic delay was 3 years (interquartile range: 0-5 years). In this cohort, N-ERD is highly variable in onset and progression, with sex, BMI, race and ethnicity, and environmental exposures significantly associated with disease patterns and diagnostic delay.