The e-commerce and technology company said sales in its cloud computing unit were up 28 per cent in the January-March period, the fastest increase in 15 quarters.
Amazon Web Services had 24 per cent sales growth in the fourth quarter, which followed the division's 20 per cent growth in the third quarter.
Net sales increased by 17 per cent year-over-year to $US181.5 billion, with growth across North America and international segments.
The Seattle-based company also offered a bullish outlook for net sales in the current quarter, surpassing analysts' estimates. However, shares slid nearly two per cent in after-hours trading.
Investors were closely watching Amazon's quarterly earnings to see if the company's $US200 billion investment in artificial intelligence, robots, semiconductors and satellites is starting to pay off.
The planned expenditure for the year marked a 60 per cent increase from Amazon's $US128 billion in capital spending last year and spooked investors, sending the stock down 11 per cent in after-hours trading when it was announced in February.
CEO Andy Jassy defended the spending during the previous quarterly earnings call, saying Amazon expected long-term returns on its invested capital.
The results from the latest quarter underscored that demand keeps growing for Amazon's services and technology.
"We're in the middle of some of the biggest inflections of our lifetime, we're well positioned to lead, and I'm very optimistic about what's ahead for our customers and Amazon," Jassy said in a release on Wednesday.
Big deals that Amazon signed with OpenAI, Anthropic and Meta this month gave the company solid momentum.
Amazon announced what it called a "major expansion" of its partnership with ChatGPT maker OpenAI on Tuesday, a day after the AI company said it was loosening its ties to longtime backer Microsoft.
Last week, Anthropic agreed to commit more than $US100 billion to Amazon's AWS cloud platform over the next 10 years to train and run the artificial intelligence company's Claude chatbot. The partnership will allow Anthropic to secure up to five gigawatts of Amazon's Trainium chips to train and power their artificial intelligence models, Amazon said.