Background/Objectives: Granulomatosis with polyangiitis (GPA) is a necrotising vasculitis characterised by granulomatous inflammation involving small vessels. In addition to specific findings for the affected organ, constitutional symptoms and joint and muscle pain can be observed. The prodromal phase, where symptoms last for months before clinical diagnosis, may suggest infection or malignancy. This may cause a delay in GPA diagnosis. The period from the first symptoms to diagnosis may last from one month to three years. In this study, we aimed to demonstrate that, as the time between the onset of symptoms and diagnosis increases, the disease involvement may become more severe, and the possibility of recurrence may increase, indicating the importance of early diagnosis. Methods: For this cross-sectional retrospective study, data from 40 patients with GPA were evaluated. Demographic, clinical, treatment, and follow-up characteristics of the patients were obtained from their medical records. Results: The mean time between the presentation of the first complaints and GPA diagnosis was 7.40 ± 11.84 (0, 60, 3; mean ± standard deviation [minimum, maximum, and median]) months. The time between the first complaints and diagnosis was longer for patients with a history of recurrence (11.44 ± 16.73 [0, 60, 4.5] vs. 4.71 ± 6.04 [0, 24, 2.5], p value = 0.260). Conclusions: GPA is an inflammatory disease with various clinical presentations. In the management of patients with GPA, awareness of its presentation is important for rheumatologists as well as other clinicians during the initial evaluation, demonstrating the importance of interclinical collaboration.