Red Cross spokesman Charles Connor said the board was not unhappy with Evans' handling of the hurricane response, "but had concerns about her management approach, and coordination and communication with the board."
Jack McGuire, the executive vice president of the charity's Biomedical Services, was named to serve as interim president and CEO while a search for a permanent successor to Evans is conducted.
Evans, a former head of the Girl Scouts of America, took over as Red Cross president in August 2002 as the organization was shaking off criticism of how it handled some of the donations sent in response to the Sept. 11, 2001, terror attacks.
The Red Cross emerged from that controversy with promises of greater openness and accountability, but the unprecedented challenges posed by this year's hurricanes raised new problems. Critics said the Red Cross failed to respond quickly enough in some low-income, minority areas; others faulted it for balking at cooperation with local grass-roots organizations even as it collected the bulk of the relief funds — more than $1.8 billion.
Evans, 58, acknowledged in September that the organization's response to Katrina and Hurricane Rita had been uneven, and said that the destructive power of the storms — along with the flooding that followed — "eclipsed even our direst, worst-case scenarios."
In recent weeks, the organization has vowed to address some of the criticisms by seeking greater diversity within its ranks and establishing partnerships with local groups.
In a statement Tuesday addressed to her colleagues, Evans said she had been thinking about leaving the Red Cross earlier, but stayed on after Katrina hit to "lead our pivotal response to that epic tragedy."
"Now, with our successful hurricane response continuing in steady hands, I believe the time is right to step down," she said. "I look forward to spending more time with my family."