Launch from Cape Canaveral (KSC); landing 500 km north of Hawaii in the Pacific Ocean.
During the launch, the second stage of the Saturn V ignited when still close to the first stage, which could have caused a catastrophic event in which the exhaust of the first stage engine would have been forced back into the engine. Despite this, the rocket nominally reached an orbit around Earth a short time later. A couple of hours into the mission, the S-IVB third stage of the rocket reignited to propel the spacecraft out of Earth orbit and on to the Moon.

A few days after launching from Florida, the spacecraft passed behind the far side of the Moon, where the Service Propulsion System engine on the Apollo Command/Service Module ignited for a six-minute burn to slow the craft down into an initial lunar orbit. Once the lowest point of altitude was reached in the orbit, the SPS engine was fired again to further stabilize the orbit of the Apollo CSM/Apollo Lunar Module stack and prepare for landing at Hadley.

The majority of the first part of the day after arriving in lunar orbit, July 30, 1971, was spent preparing the Lunar Module for the descent to the lunar surface later on that day. After preparations were complete, un-docking from the CSM was attempted, but did not occur because of the faulty seal in the hatch mechanism. Command Module Pilot Alfred Worden re-sealed the hatch and the LM then successfully separated from the CSM. David Scott and James Irwin continued preparations for the descent while Alfred Worden remained in the CSM, returning to a higher orbit to perform lunar observations and await their return a few days later.

Soon thereafter, David Scott and James Irwin began the descent to the Hadley landing site on the surface. Several minutes after descent was initiated, at pitch-over and the beginning of the approach phase of the landing, the LM was six kilometers east of the pre-selected landing target. Upon learning of this, David Scott altered the flight path of the LM and touched down at 22:16:29 UTC on July 30, 1971 at Hadley, within a few hundred meters of the planned landing site. While previous crews had exited the Lunar Module shortly after landing, the crew of Apollo 15 would be spending a substantially longer amount of time on the surface than previous crews. In order to preserve their sleep rhythm, the crew elected to spend the rest of the day inside the LM and wait until the next day to perform the first of three Extra-vehicular activities (EVAs), or moonwalks. Before beginning their sleep period, David Scott performed a stand-up EVA, during which the LM was depressurized and the top docking hatch opened to allow him to photograph their surroundings.

The mission was the fourth moon landing in space history. The landing site was the Hadley Apennine region near Apennine Mountains. Lunar surface stay-time was 66h 55m.

Three EVAs were performed by David Scott and James Irwin. The first EVA occured on July 31, 1971 (6h 33m). The astronauts collected and stowed a contingency sample, unpacked the ALSEP and other experiments, and prepared the lunar roving vehicle (LRV) for operations. The LRV was used for the first time.

The second EVA was performed on August 01, 1971 (7h 12m). During this EVA the crew completed the placement of heat flow experiment probes (which were emplaced during the first EVA traverse), collected a core sample, and deployed the American flag. They also stowed the sample container and the film with photos from the Elbow and St.George crater near the Hadley-Rille into the LM (Falcon).

The third and final EVA by David Scott and James Irwin was performed on August 02, 1971 (5h 01m). During the third EVA Commander David Scott struggled and fell but experienced no difficulty in getting up. Prior to leaving the lunar surface, David Scott performed an experiment, which Galileo Galilei described 300 years earlier. In one hand a hammer and in the other a falcon feather, David Scott let fall down both to the same time, and both dropped on the lunar surface to the same time - so Galileo Galilei was right. All in all 77.31 kg of material were gathered.

After lifting off from the lunar surface 2 days and 18 hours after landing, the LM ascent stage rendezvoused and re-docked with the CSM with Alfred Worden aboard in orbit. After transferring samples and other items from the LM to the CSM, the LM was sealed off, jettisoned, and intentionally crashed into the lunar surface. After completing more observations of the Moon from orbit and releasing the sub-satellite, the three-person crew departed lunar orbit with another burn of the SPS engine

Alfred Worden performed a 39 minutes trans Earth EVA on August 05, 1971 to remove film cassettes from the cameras in the scientific instrument module. He had completed 34 lunar orbits in the CSM (called Endeavour), while his fellow astronauts were on the lunar surface, and performed several scientific instrument module experiments and cameras to obtain different data.

One of the three main parachutes failed. That results in hard splashdown. The recovery ship was the USS Okinawa.