Background Sweet's syndrome (SS) is a neutrophilic dermatosis characterized by the abrupt onset of cutaneous, systemic and histopathological alterations in response to different stimuli. Objectives The aim of this study was to assess the epidemioclinical, histological, and therapeutic features and outcomes of SS. Methods A retrospective study of all patients diagnosed with SS over a 20-year period (1993–2012) was conducted. Data were analyzed using a level of significance of 5%. Results Ninety patients (mean age: 46.5 years) fulfilled the inclusion criteria. The ratio of women to men was 5. Significant associations emerged between dermohypodermic nodes and location on the lower limbs (P = 0.042), and vesiculobullous lesions and location on the legs (P = 0.030), dorsum of the hand (P = 0.015), and forearms (P = 0.003), and paraneoplastic forms (P = 0.012). The upper extremities were involved in the majority of patients (83.3%). Correlations were found between edema of the superficial dermis and vesiculobullous lesions and between leukocytoclastic vasculitis and atypical targetoid lesions. Sweet's syndrome was associated with cytomegalovirus infection (n = 1), inflammatory bowel disease (n = 4), neoplasm (n = 6), and pregnancy (n = 3). First-line treatment consisted of colchicine. Conclusions To the best of the present authors' knowledge, this is the largest series of SS to be reported. Clinical presentations are similar to those described in the literature. Colchicine was efficient and facilitates the reduced use of corticosteroids. The association between SS and neoplasms should be considered in the context of vesiculobullous lesions.