A two-year study in Leuven, Belgium, compared respiratory virus detection in wastewater with clinical samples to assess community spread. Wastewater data reflected circulation levels of seasonal respiratory viruses like influenza, RSV, and enterovirus D68. Wastewater-based surveillance has been used since the COVID-19 pandemic to track SARS-CoV-2, showing it as an objective indicator of community circulation, especially when testing is limited. Many people with acute respiratory infections do not seek medical care, making wastewater sampling a valuable tool for monitoring population-level virus circulation. The study analyzed 112 wastewater samples collected weekly over two years using a multiplex quantitative PCR panel. The results showed that respiratory viruses detected in wastewater corresponded with clinical samples from patients at University Hospitals Leuven (UZL), though clinical samples were not fully representative of all circulating pathogens. Influenza A was detected in wastewater during mid-February to mid-May 2022, aligning with clinical data. RSV had an off-season peak in 2021, reflected in wastewater samples, and reappeared in 2022. Human metapneumovirus was continuously detected in wastewater, matching high clinical sample numbers. Parainfluenzaviruses showed seasonal patterns, with PIV-1 peaking in fall 2022. Adenovirus and human bocavirus were consistently detected in wastewater, suggesting enteric rather than respiratory infections. Enterovirus D68 was detected in 2021, with a regional outbreak, and reappeared in 2022. Human parechovirus was detected in wastewater but had few clinical cases, possibly due to paucisymptomatic infections. The study highlights the potential of wastewater sampling for population-level pathogen monitoring and early outbreak detection, complementing clinical surveillance. It underscores the role of wastewater-based epidemiology in understanding community virus circulation and supporting public health efforts. The findings demonstrate the value of wastewater surveillance in tracking respiratory viruses, especially when clinical data is limited.A two-year study in Leuven, Belgium, compared respiratory virus detection in wastewater with clinical samples to assess community spread. Wastewater data reflected circulation levels of seasonal respiratory viruses like influenza, RSV, and enterovirus D68. Wastewater-based surveillance has been used since the COVID-19 pandemic to track SARS-CoV-2, showing it as an objective indicator of community circulation, especially when testing is limited. Many people with acute respiratory infections do not seek medical care, making wastewater sampling a valuable tool for monitoring population-level virus circulation. The study analyzed 112 wastewater samples collected weekly over two years using a multiplex quantitative PCR panel. The results showed that respiratory viruses detected in wastewater corresponded with clinical samples from patients at University Hospitals Leuven (UZL), though clinical samples were not fully representative of all circulating pathogens. Influenza A was detected in wastewater during mid-February to mid-May 2022, aligning with clinical data. RSV had an off-season peak in 2021, reflected in wastewater samples, and reappeared in 2022. Human metapneumovirus was continuously detected in wastewater, matching high clinical sample numbers. Parainfluenzaviruses showed seasonal patterns, with PIV-1 peaking in fall 2022. Adenovirus and human bocavirus were consistently detected in wastewater, suggesting enteric rather than respiratory infections. Enterovirus D68 was detected in 2021, with a regional outbreak, and reappeared in 2022. Human parechovirus was detected in wastewater but had few clinical cases, possibly due to paucisymptomatic infections. The study highlights the potential of wastewater sampling for population-level pathogen monitoring and early outbreak detection, complementing clinical surveillance. It underscores the role of wastewater-based epidemiology in understanding community virus circulation and supporting public health efforts. The findings demonstrate the value of wastewater surveillance in tracking respiratory viruses, especially when clinical data is limited.