Reilly will be replaced on a temporary basis by Chairman Martin Cole. Cloudera has begun a search for a permanent CEO.
"Tom and the board have always been committed to continually evaluating Cloudera's progress and ensuring that we are executing to drive long-term value. Accordingly, we have mutually agreed with Tom that this is the right time for a leadership transition," Cole said in a statement.
The cloud software company posted a first-quarter adjusted loss of 13 cents a share on revenue of $187.5 million. Analysts expected a loss of 23 cents a share on revenue of $188.4 million.
For the second quarter, Cloudera expects a loss of 8 cents to 11 cents a share on revenue of $180 million to $183 million. Analysts forecast a loss of 10 cents a share on revenue of $202.9 million.
The company said it expects fiscal-year revenue of $745 million to $765 million, well below analysts' estimates of $844.7 million. The company expects to post an adjusted loss of 28 to 32 cents a share, narrower than Wall Street's calls for a loss of 35 cents.
Bernstein's Zane Chrane lowered his rating on the stock to market perform from outperform.
"Our downgrade is based on what we believe is most likely accelerating structural headwinds from cloud vendor competition, with no visible catalysts for multiple expansion or upward revisions in the next three to six months," the analyst said.
Chrane reduced his price target on shares of Cloudera to $7 from $15.
Stifel cut its rating to hold from buy and the price target to $6 from $16.