David H. Petraeus, who was cautioned against bringing an entourage with him to the CIA, arrived for his first day as director Tuesday without a single military aide in tow.

The solo nature of the Petraeus start runs counter to his reputation in the military, as well as recent history at the CIA.

His predecessor, Leon E. Panetta, brought along a new chief of staff, and eventually took two other CIA aides with him after he became secretary of defense.

Panetta’s predecessor, Michael V. Hayden, came with a legal adviser he had come to trust at NSA. And Porter Goss arrived with a contingent of former congressional staffers who were derisively dubbed “the Gosslings” by veterans at an agency that has a long history of allergic reactions to outsiders entering its upper ranks.

With Petraeus, there was particular concern that an imported staff would give the military too much influence in a civilian agency that has increasingly assumed paramilitary functions. That concern helped prompt Petraeus to retire and remove his uniform before taking the job.

During his decorated U.S. Army career, Petraeus was known for being followed by an extensive staff of advisers as he moved from one command post to another. He may add new hires after he settles into the job, but U.S. officials said his immediate staff is already intact.

His chief of staff is Rodney Snyder, a CIA analyst who also served as the intelligence chief for the Department of Homeland Security. Michael J. Morell, who served as acting director of the CIA after Panetta stepped down, will resume his deputy role.

Petraeus, who retired from the military after a 37-year career last month, wore a civilian suit as he was sworn in by Vice President Joe Biden. “There’s literally no time to waste,” Biden said. “The president wants him on the job.”

Indeed, 15 minutes after the White House ceremony began, Petraeus was in the Oval Office for President Obama’s daily intelligence brief.