Urinary tract infections (UTIs) are among the most common complications following kidney transplantation, affecting 25–75% of recipients. Current diagnosis relies on culture-based methods requiring several days for pathogen identification and antimicrobial susceptibility testing, delaying targeted treatment. To address this, qPCR assays were combined and analytically validated into two complementary multiplex panels targeting bacterial pathogens responsible for approximately 85% of UTIs in kidney transplant recipients. Both multiplex assays were optimised to operate under identical cycling conditions, enabling simultaneous analysis. The first triplex targets bacterial 16S rRNA, Escherichia coli and Klebsiella pneumoniae, while the second targets Enterococcus faecalis, Staphylococcus saprophyticus and Proteus mirabilis. Analytical validation included optimisation of multiplex conditions, assessment of amplification efficiency, linearity, analytical sensitivity and analytical specificity. Both multiplex panels demonstrated amplification efficiencies of 90–110%, R² values exceeding 0.98 for all six targets, no significant cross-amplification, and limits of detection below 150 copies per reaction. Compared with conventional culture, multiplex qPCR demonstrated greater analytical sensitivity, detecting bacterial pathogens below conventional diagnostic thresholds. Together, these complementary multiplex panels provide a rapid molecular diagnostic approach with the potential to facilitate earlier diagnosis and targeted antimicrobial therapy, reducing reliance on empirical broad-spectrum antibiotics in kidney transplant recipients.