The adjusted net income per share was US$0.65 on a diluted basis, up 62% from US$0.40 per share in the same quarter a year earlier.
"The company [is] in a strong position to execute on initiatives targeting approximately 100,000 tonnes of annual copper production and 60,000 ounces of annual gold production by 2025," said chief executive David Strang.
ASCI gold costs increased 50% to US$910 an ounce from US$608 an ounce over the same period.
The firm stuck to guidance that ASCI costs would rise further to $925-$1,025 an ounce this year, based on a gold price of US$1,725 an ounce.
Ero's copper production in the fourth quarter of last year totalled 11,918 tonnes, up 19% from 10,018 tonnes produced a year earlier.
This was a result of increased mill throughput volumes related to the ramp-up of mining activity and processing of stockpiled ore at the Surubim open pit and the return to higher mill capacity levels following the completion of mill maintenance.
Gold production fell 20% to 8,544 ounces from 10,789 ounces.
Ero Copper's copper mining and development operations are located in north-eastern Brazil within the states of Bahia and Pará.
Shares in Ero Copper on the Toronto Stock Exchange were quoted 1.48% or C$0.29 higher at C$19.88