The hospital water environment is an important reservoir of multidrug-resistant organisms (MDROs) and presents a risk for patient safety. We assessed the effectiveness of thermal and chemical interventions on sinks contaminated with MDRO in hospital setting. We conducted a cross-sectional assessment of MDRO contamination of sinks and toilets in 26 clinical wards of a tertiary care hospital. MDRO-contaminated sink traps were then replaced and randomized (1:1:1) to receive chemical (sodium hypochlorite), thermal disinfection (steam), or no intervention. Interventions were repeated weekly for four weeks. Sinks were resampled seven days after the last intervention. The primary outcome was the proportion of decontaminated sinks. MDROs of interest were extended-spectrum beta-lactamase-producing and carbapenemase-producing s Enterobacterales, and non-fermentative Gram-negative bacilli. In the cross-sectional assessment, at least one MDRO was identified in 258 (36%) of the 748 samples and in 91 (47%) of the 192 water sources. In total, 57 (42%) of the 137 sinks and 34 (62%) of the 55 toilets were contaminated with 137 different MDRO. The most common MDRO were ESBL-producing Enterobacterales (69%, 95/137), followed by VIM-producing P. aeruginosa (9%, 12/137) and Citrobacter spp. (6%, 5/137). In the nested randomized trial, 5 of 16 sinks (31%) in the chemical disinfection group were decontaminated, compared to 8 of 18 (44%) in the control group (OR 0.58, 95%CI 0.14-2.32) and 9 of 17 (53%) in the thermal disinfection group (OR 1.40, 95%CI 0.37- 5.32). Our study failed to demonstrate an added benefit of repeated chemical or thermal disinfection, beyond changing sink traps, in the MDRO decontamination of sinks. Routine chlorine-based disinfection of sinks may need to be reconsidered.