Traffic police officers Sergeant Fadli Shaifuddin Mohamed Sani and Corporal Ng Ching Heng were conducting a road block along Jurong Road in July this year, when they stopped a female driver who was suspected of drink-driving.
After she failed a breathalyser test, she offered the officers $3,000 as a bribe and begged them to let her go.
The two refused her offer and took the 38-year-old woman back to the Traffic Police headquarters for a second breathalyser test.
"We had no second thoughts," said Sgt Fadli, who has been a traffic police officer for three years.
"It's within us to not accept the money. If we don't stop corruption, who will?"
Sgt Fadli, 26, and Cpl Ng, 34, were among 10 officers who received commendation certificates for rejecting bribes at this year's Singapore Police Force Service Medals Presentation Ceremony.
The ceremony took place yesterday at the Home Team Academy in Chua Chu Kang, with Commissioner of Police Ng Joo Hee giving out the certificates.
A total of 741 police officers received medals for good service and length of service.
This was Sgt Fadli's third time getting the commendation certificate, and Cpl Ng's second.
Police statistics show that the number of bribery cases has declined in the past three years, from 20 in 2010 to 16 last year.
Last year, Singapore was ranked the fifth least corrupt out of 176 countries and territories on watchdog Transparency International's Corruption Perception Index, coming after Denmark, Finland, New Zealand and Sweden.