Like most ancient Indian armies, the Mauryan army had 4 types of troops- elephant (gaja), chariot (ratha), cavalry (turanga), and infantry (pada).

The army was broken into many units. The smallest unit was called a patti, and had 1 chariot, 1 elephant, 3 cavalry and 5 infantry. The elephant and chariot would typically be in the center with the cavalry and infantry surrounding them. Three patti made up a Sena mukha, and three Sena Mukha made up a Gulma. Other divisions were the Gana, Vahini, Pratana, Camu and Ani kini, each of which was three times as big as the one preceding it. The Aksauhini was composed of ten Ani kini, and was the largest unit in an army.

The Mauryan army had multiple Aksauhini's. The standing army had three-quarter million troops, one of the largest armies in the world at the time.

A variety of formations were used in the Mauryan army. Formations were known as vyuha, each one had a center, two flanks and two wings. There were thirty main vyuha used, divided into four main categories. One example of a vyuha would be the Padma vyuha or lotus formation.

It would be easy to visualise the 'padma vyuha' if it is imagined as a six pointed star. The Deputy Commanders-in-Chief would be placed at each outer point of the petals and at the inner end, where each end of lotus petal joins with the other, to form an inner-circle resembling the corolla of the lotus, the Commanders-in-Chief would be stationed. The space between any two 'petals' is the only access to reach the centre of the 'lotus' where the Supreme Commander was placed. If a contingent of enemy soldiers moved between any two petals for this purpose, the petals would close in and crush the invader like the powerful tentacles of a crab.

The Garuda Vyuha or eagle formation was another commonly used formation.

The Garuda Vyuha had a 'beak' where the best elite Kshatriya soldiers would be placed in tight wedge formation. The 'head,' behind the beak had a small contigent of reserves, also of good quality. Often, war elephants would be placed in the beak and head. Two broad 'wings' would sweep out behind the head, with the swiftest troops- the chariots and cavalry at the outside. Behind the wings, the body, would consist of reserves.

Some other formations:

Suchi Vyuha- Needle formation

Chayana Vyuha- Hawk formation

Mala Vyuha- Garland formation

Karuncha vyuha- Heron formation

Makara vyuha- Fish formation

Padma vyuha- Lotus formation

Kurma vyuha- Turtle formation

Trishula vyuha- Trident formation

Chakra vyuha- Wheel or Discus formation

Garuda vyuha- Eagle formation

The Mauryan army was composed of people all over the subcontinent. In addition, Chandragupta Maurya did not discriminate against different castes, as he was of low caste himself (reputedly he was the son of a peacock tamer ). As a result, there were soldiers in his army from all castes, making the army very diverse.

The core of the army was composed of Uttarapathian warriors, from central and western India. Uttarapatha had many militaristic peoples – like the Kambojas, Yavanas, Sakas and Vardas. Other peoples in the Mauryan army were the Maghadas, Assamese, and Cheras. Even the Nagas (literally serpents, because they worshiped cobras), a mystical people to the east, were incorporated into the army.

Mauryan commander