The stock slumped 7.6% to $16.56.
The company posted a loss of 3 cents a share, adjusted for one-time items, in the first quarter on revenue of $163 million. Analysts had been expecting Box to lose 5 cents a share on revenue of $161.5 million.
Box expects second-quarter revenue of $169 million to $170 million, and revenue for the fiscal year of $688 million to $692 million. Analysts forecast second-quarter revenue of $170.9 million and revenue of $702 million for the year.
Box is pursuing larger strategic sales, but "these deals often have longer sales cycles, which is reflected in our updated guidance," said CEO Aaron Levie in a press release.