The company said daily active usage increased 14% year-over-year, the fourth consecutive quarter of accelerating growth, but didn't disclose actual figures for its average daily user base.
Twitter shares were 12% up in pre-market trade after its latest results beat expectations - highlighting its strongest user growth for more than a year. Given Twitter's recent sales trends and the fact that the company stopped providing quarterly sales guidance last fall, many analysts clearly feared the worst, and Twitter didn't deliver that.
"While we face revenue headwinds, we made progress focusing revenue products on our strengths", Dorsey said, adding that user growth will contribute to revenue and profit going forward. More users, of course, mean more advertising revenue for the companies, since businesses try to reach as many eyeballs as possible.
So it was surprising that despite Trump's incessant tweeting during the USA election last fall, Twitter added just two million new users in the last three months of the year.
Revenue fell 7.8% to $548.3m, its first drop since its initial public offering.
Twitter on Wednesday reported better-than-expected performance for the first quarter which sent shares soaring more than 10 percent.
Mr Dorsey said the increase in users was in part because the service had been streamlined to make it a better experience for users, including measures to reduce abusive content.
Monthly users of Twitter grew 6 percent from a year ago to 328 million.
The social messaging app has been trying to improve its user experience and keep people more engaged, a challenge now that the dramatic US election campaign is over.
Trump's tweets generate headlines on a daily - if not hourly - basis, ensuring Twitter is constantly in the news cycle. Twitter saw a larger revenue decrease in the US, with a 13% year-over-year decline. It reported adjusted earnings per share of 11 cents, above the FactSet consensus of 2 cents.
"We believe Twitter is the best place to drive brand perception, and we're continuing to showcase our unique value proposition for advertisers", said Anthony Noto, Twitter's COO, in the shareholder letter.