Microsoft sold 73% fewer Lumia smartphones over the past three months compared to the same period last year, while mobile revenue for the quarter dropped by 46%.
The company released these figures as part of its latest quarterly results, which painted a poor picture of its smartphone business.
Engadget reported that in the quarter preceding the latest period, Microsoft suffered a phones sales drop of 54%.
This also follows reports from January that the Windows Phone is dead, based on sales data.
The company is still making a profit off its smartphones, though – with net profit at $3.8 billion.
Microsoft had more positive news when it came to its Surface business, which has shown a 61% growth year-on-year.
The company said the Surface Pro 4 and the Surface Book contributed to the rise in sales.