The Corolla and Camry maker reported net profit of 646 billion yen (USD 5.2 billion) in the three months to June, beating analyst expectations, while revenue rose 9.3 per cent to 6.98 trillion yen.
The Japanese giant's vehicle sales, however, were slightly lower in the period and it trimmed its 2015 calendar year sales forecast to 10.12 million vehicles from 10.15 million units.
Toyota and Volkswagen are locked in a tight race for the title of world's biggest automaker this year, after the German giant outsold its Japanese rival in the first half.
The Japanese currency's steep slide has helped make automakers more competitive overseas and inflated the value of repatriated overseas profits.
"Toyota has benefited from the weak yen and strong sales in North America, while sales of its Lexus models have been steady," said Tokyo-based auto analyst Takaki Nakanishi.
Last quarter, sales in the key North American market rose, while they turned down in Europe and Asia - including Toyota's home market Japan, where consumer spending dived after the government raised sales taxes last year.
"There has been a change in the environment" in China, he told reporters.
"For the time being, we have not seen an impact on our sales, which have been increasing in recent months, but stock markets are falling and other indicators are mixed, so we want to be vigilant."
Separately, Toyota said it was reorganising its Chinese operations, including adding a production line at a plant in the northern city of Tianjin with a capacity of 100,000 vehicles annually to replace an older assembly line.
Toyota has been focusing on squeezing out productivity gains and better using existing plants - it put on hold building new factories for several years.
