The Japanese firm said it made a profit of ¥108.7bn (£551m) for the period between April and September, down from ¥271bn (£1.37bn) in the same period last year.
The company’s results also showed a 34% drop in sales – most of which came from Nintendo Switch hardware and software – including in Europe, where Switch sales fell from ¥175.8bn (£889m) last year to ¥113.2bn (£573m) this year.
The Switch console has been a huge success for Nintendo since it first launched in March 2017, offering a combination of home console and remote play via a portable screen and console dock connected to a TV.
Since then, however, the device has seen only incremental updates — including an OLED screen version and a cheaper Switch Lite — and momentum around the device seems to be waning.
According to Nintendo data, global sales of Switch machines fell to 4.7 million from 6.8 million in the same period last year.
And despite near-constant questions and rumors about a successor to the Switch, Nintendo has yet to confirm or announce any details about a next-gen version of the device.
But Nintendo said in a statement that Switch sales were still growing and promised to stick to its goal of selling a Switch console to every individual, not just one Switch for every household.
Nintendo stuck to its previous profit forecast of ¥300bn (£1.54bn) for the full fiscal year to March 2025, down nearly 29% from the previous fiscal year.
Annual sales are forecast to fall 23% to 1.28 trillion yen (£6.5 billion).
It also lowered its sales forecast for the Switch for the fiscal year to 12.5 million units from an earlier sales forecast of 13.5 million.