Background: Our study examined the prevalence, types of human respiratory syncytial virus (HRSV), and sequence variability of the attachment glycoprotein (G) gene among symptomatic children under 18 in Hungary between 2017 and 2023. Methods: We retrospectively determined the type of HRSV strains and analysed their G protein sequence and aminoacid polymorphism in respiratory samples before and after the SARS-CoV-2 pandemic. Results: We confirmed the presence of HRSV-A in 233 (12.74%), HRSV-B in 235 (13.85%), and both in 5 cases (0.27%). The subtype pattern was HRSV-B in 2017 and 2022-2023, and HRSV-A in 2017-2022. The highest HRSV positivity (38%) could be observed between 2018 and 2019, while the lowest was in the 2017-2018 season. The median age of HRSV-positive patients was 7.09 months, and we did not show a significant difference in their median age between the seasons. During the SARS-CoV-2 pandemic, the HRSV season has an earlier onset and longer duration than before. All HRSV-A isolates are classified into the A.D clade, HRSV-B strains have belonged to B.D. clade. We found characteristic mutations in the HRV1 region of the G gene in the HRSV-A A.D strains during the 2019 and 2020 seasons, forming a distinct lineage closely related to only two German isolates. The HRSV-B B.D strains between 2022 and 2023 carried mutations in the HRV2 region, reported from several countries. Discussion: The SARS-CoV-2 pandemic caused changes in the seasonal appearance of HRSV infections. G protein sequence modifications in Hungarian HRSV strains can support the need for their molecular characterisation.