Third-quarter operating profit rose 77.6% to 444 million euros (£384 million) from 250 million a year earlier, it said.
That topped the 420 million expected by analysts, Refinitiv data showed.
Neste, which is 44.7% state owned, is investing heavily in renewables, which accounted for 70% of group profits in the quarter.
A 1.4 billion euro investment in its Singapore refinery's renewables output - its biggest single investment to date - is "proceeding as planned," it said, with increased output scheduled to begin in mid-2022.
The refinery produces renewable fuels, mainly from waste and residue such as used cooking oil, animal fat from food industry waste, fat from fish processing waste and residue from vegetable oil processing.
Neste said its renewables unit's comparable operating profit rose 34% to 305 million euros buoyed by a 30% rise in sales volumes.
Analysts at Credit Suisse stressed the unit's "strong operational performance."
Neste's revenue in the third quarter rose to 3.96 billion euros, beating analysts' forecasts of 3.75 billion euros.
"Demand for renewable diesel is expected to remain strong in the fourth quarter in anticipation of the growing mandates in 2020," Neste said.
Neste said utilisation rates at its renewables production facilities would remain high, except for a scheduled four-week catalyst change at its Rotterdam refinery.
It said it has been able to halve an expected 50 million-euro dent in its earnings from the maintenance by building up inventory.
Neste's shares jumped to their highest level in 6 months on Wednesday and were up 6.8% in early afternoon trade at 31.79 euros, valuing the firm at 24.5 billion euros.
Last week Neste was hit by IT problems which delayed fuel deliveries after a systems failure at its service provider's data centre.
Neste Chief Executive Peter Vanacker told Reuters the situation had stabilised but it was too early to evaluate costs as crisis management work was continuing this week.
Neste wrote down assets worth 34 million euros at Nynas AB -- a joint venture with Venezuela's state-run PDVSA -- retaining its stake but fully writing off the shareholding in financial terms. Vanacker said its results will not be consolidated going forward.
Earlier this week Nynas said it will suspend imports of Venezuelan crude following changes to a licence allowing it to operate under U.S. sanctions.
"We continue to focus on the viability of Nynas," Vanacker said.
Nynas operates speciality refineries in Sweden, Germany and England, mostly for asphalt production.
Neste will implement a scheduled 11-week major turnaround at its Porvoo refinery -- the largest ever for the company -- in the second quarter of 2020 that is expected to hit its renewable unit's operating profit by some 40 million euros.
(Reporting by Anne Kauranen and Tarmo Virki; editing by Tom Hogue, Jason Neely, Kirsten Donovan)
By Tarmo Virki