Objective To analyze the epidemiological characteristics and pathogen spectrum of acute respiratory infections in sentinel hospitals in Yangpu District, Shanghai, 2024, and to provide evidence for the development of precise prevention and control strategies. Methods Clinical and laboratory data were collected from outpatient/emergency influenza-like illness (ILI) cases and hospitalized severe acute respiratory infection (SARI) cases in sentinel hospitals of Yangpu District between Jan. 1 and Dec. 31, 2024. Epidemiological characteristics and seasonal epidemic patterns of pathogens of acute respiratory infections were analyzed using descriptive statistics, and intergroup differences were analyzed using χ² test and Fisher exact test. Results A total of 2 514 cases were enrolled, including 1 360 outpatient/emergency ILI cases and 1 154 hospitalized SARI cases, with an overall pathogen detection rate of 46.5% (1 168/2 514). The most common clinical manifestations were fever (99.4%, 2 500/2 514) and cough (93.4%, 2 348/2 514). The top 3 pathogens were Mycoplasma pneumoniae (10.3%, 259/2 514), adenovirus (7.2%, 180/2 514), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; 6.8%, 171/2 514). Among outpatient/emergency ILI cases, the elderly aged ＞60 years had the highest detection rate of pathogens (61.4%, 51/83), with SARS-CoV-2 being the predominant (38.6%, 32/83). Among hospitalized SARI cases, children aged ＞4-15 years had the highest detection rate of pathogens (46.1%, 166/360), with Mycoplasma pneumoniae as the primary pathogen (36.9%, 133/360). The most common mixed infections were coinfection with human coronavirus HKU1 and human coronavirus NL63 (44 cases, 41.9%) and coinfection with enterovirus and human rhinovirus (34 cases, 32.4%). Seasonal trends showed that adenovirus infection peaked in summer (May to Aug.), influenza virus infection in winter (Jan. to Feb. and Dec.), SARS-CoV-2 infection exhibited bimodal peaks in late winter to spring (Feb. to Mar.) and in summer (Jun. to Aug.), while Mycoplasma pneumoniae infection persisted epidemic throughout the year among hospitalized SARI patients. Conclusion Acute respiratory infections demonstrate distinct age and seasonal variations in Yangpu District, Shanghai, 2024. Tailored public health prevention and control interventions should be implemented, including adenovirus infection control for children aged ≤15 years and SARS-CoV-2 infection prevention for the elderly aged ＞60 years, as well as enhancing the management of Mycoplasma pneumoniae infection in hospitalized SARI patients.