The Broncos five-eighth on Monday pleaded guilty to driving while relevant drug is present in blood after the two-vehicle crash in Brisbane's inner west on October 18.
The 21-year-old also entered a guilty plea for driving without a licence.
Mam arrived at a packed Brisbane Magistrates Court on Monday wearing a dark suit and supported by his mother.
He was charged after driving a Ford Ranger that stuck a Toyota Camry travelling in the opposite direction in Bardon.
The Broncos playmaker underwent a roadside drug test and returned a positive result.
A secondary test later was also positive.
The magistrate said Ezra Mam was fortunate not to have killed or injured anyone. (Russell Freeman/AAP PHOTOS)
Mam was fined $850 and had his licence suspended for six months.
No conviction was recorded but the magistrate chastised Mam for his actions.
"Having made that stupid decision to get behind the wheel of the car, and using illicit substances as well … a cocktail of cocaine and other matters that were found in your blood on this particular occasion," the magistrate said.
"At so many levels you are fortunate to stand where you are today given you were involved in a two vehicle motor accident. You could've been injured or killed or the other parties could've been injured or killed."
Mam is at risk of a lengthy NRL ban.
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