Accurate and rapid identification of carbapenemase-producing Gram-negative bacteria is essential for appropriate antimicrobial therapy and infection control. This study compared the diagnostic performance of two multiplex lateral flow immunoassays, the NG-Test CARBA 5 (NG) and a Colloidal Gold Immunoassay (CGI), for the detection of major carbapenemases in clinical isolates of Klebsiella pneumoniae and Pseudomonas aeruginosa. A total of 100 non-duplicate carbapenem-resistant isolates collected in 2024 were included. An in-house polymerase chain reaction assay targeting blaKPC, blaNDM, blaVIM, blaIMP, and blaOXA-48-like genes served as the reference standard. Overall, the NG assay demonstrated higher sensitivity than the CGI assay, while both tests showed excellent specificity. For OXA-48-like enzymes, both assays exhibited 100% specificity and 89.6% sensitivity. Detection of NDM was more sensitive with NG (96.9%) than with CGI (87.7%), whereas both maintained 100% specificity. For KPC detection, NG achieved 100% sensitivity, while CGI showed a markedly lower sensitivity (73.7%). Diagnostic performance was generally superior in K. pneumoniae compared with P. aeruginosa, and both assays showed reduced sensitivity in isolates co-harboring multiple carbapenemase genes. These findings indicate that although both lateral flow assays are rapid and practical tools for routine laboratory use, their performance may vary depending on the carbapenemase type and local epidemiology. Molecular confirmation remains essential, particularly in settings with a high prevalence of multiple carbapenemase-producing isolates.  Kulcsszavak: lateral flow immunoassay, carbapenemase, NG test, colloidal gold immunoassay, Klebsiella pneumoniae, Pseudomonas aeruginosa