Reid suffered rib and hip contusions in the crash that happened about 1:10 p.m. Friday on Interstate 15, staffers said. He was taken to the hospital by his security detail as a precaution. Troopers had earlier reported he was transported by ambulance.
Reid, 72, was wearing a seatbelt at the time of impact, and walked into the hospital on his own.
Reid officials say other members of the senator's security detail and a staffer had minor injuries and were taken to the hospital for evaluation.
Six vehicles were involved in the apparent chain-reaction crash, including two Las Vegas police vehicles and two Capitol Police vehicles that were escorting Reid. Images from the scene showed broken glass, bumper damage and deflated tires on some of the vehicles.
Two lanes were closed and four tow trucks were summoned to the freeway that runs parallel to the Las Vegas Strip, Nevada Highway Patrol spokesman Jeremie Elliott said.
Officials in Reid's office said it wasn't immediately clear where Reid was headed at the time of crash.
Earlier, Reid took part in a ceremony honoring the National Atomic Testing Museum in Las Vegas as the newest "national" museum. The museum's exhibits focus on the history of the development and testing of a nuclear bomb.
He was also due to speak to the editorial board of Spanish-language newspaper El Tiempo at 2:30 p.m., according to editor Hernando Amaya.
Reid's wife, Landra, was speaking at a Las Vegas event featuring first lady Michelle Obama at roughly the time the crash happened, but she was not involved and made no mention of the incident during her remarks.
In March 2010, Reid's daughter, Lana, and wife were injured when a tractor-trailer slammed into their minivan while they were returning from a shopping trip in Virginia. Landra was left with a broken back, neck and nose and daughter Lana suffered minor injuries.
Reid, who has served as state legislator, lieutenant governor, congressman and five-term senator, has been majority leader since 2007.
As the top Democrat in the Senate, he helped steer President Barack Obama's health care overhaul to passage in 2010 and secured his own re-election later that year, a surprise win in a Republican wave. Reid defeated tea party-backed candidate Sharron Angle despite early prognostications that the Democrat was one of the most vulnerable in the congressional elections.
The past two years, with Republicans controlling the House, Reid has thwarted the House GOP, protecting Obama's agenda and angering Senate Republicans.