Adeno-associated viral (AAV) vectors are widely used for gene therapy, providing treatment for diseases caused by absent or defective genes. Despite the success of gene therapy, AAV-manufacturing is still challenging, with production yields being limited. With increased patient demand, improvements in host cell productivity through various engineering strategies will be necessary. Here, we study the host cell proteome of AAV5 producing HEK293 cells using reversed phase nano liquid chromatography and tandem mass spectrometry (LC-MS/MS). Rela-tive label-free quantitation (LFQ) was performed allowing a comparison of transfected vs. un-transfected cells. Gene ontology enrichment and pathway analysis revealed differential expres-sion of proteins involved in fundamental cellular processes such as metabolism, proliferation and cell death. Furthermore, changes in expression of proteins involved in endocytosis and lysosomal degradation were observed. Our data provides highly valuable insights into cellular mechanisms involved during recombinant AAV production by HEK293 cells thus potentially enabling further improvements of gene therapy product manufacturing.