Reliefs depicting scenes from the life of Shakyamuni Buddha as well mythological figures like yakshas and yakshis, sculptures on the Amaravati Mahachaitya are considered the most important examples of the Amaravati school of art. Though the construction of the stupa was initiated in the third century BCE, railings carrying these relief sculptures were added gradually, continuing from the mid-first century BCE to the early third century CE.

The primary remains of the Amaravati mahachaitya today consist of fragments from the railings, as well as various cross-sections, pillars, slabs, and friezes; most of these are carved with mid-relief sculptures. The railings around the stupa measured 200 centimetres in height and hundred centimetres in width, with a depth of thirty-five centimetres; the crossbars on the railings measure between approximately forty and seventy centimetres, with the pillars measuring approximately three metres in height.

The outer faces of the pillars are decorated with the motif of a fully-bloomed lotus in the centre, with half lotuses on the ends: in Buddhist iconography, the flower represents purity and the enlightenment of the Buddha. Their inner faces narrate the life of the Buddha. However, rather than depicting the narrative on smaller sections of the pillar as seen on Sanchi Stupa, the entire face is used for depicting one story. As such, the flow of narrative varies considerably across the pillars. Some scenes are designed to be read from the top to the bottom of the pillar, while others start at the centre and move towards the edges. Scholars have studied these relief sculptures for their naturalistic representation of action and innovative utilisation of space, typically depicting multiple figures surrounding the lotus medallions. The figures themselves possess intricately detailed physiological features.

Since the relief sculptures were added over many centuries, the sculptural art of the Amaravati mahachaitya offers a glimpse into evolving traditions of depicting the Buddha, as well as Buddhist artistic interactions across the subcontinent. The earliest representations were symbolic and aniconic, using motifs such as a pair of footprints to signify his presence; these are accompanied with inscriptions suggesting they were commissioned in the first century BCE as part of a single phase of construction. Later sculptures used both iconic and aniconic depictions, using an anthorpomorphic form to depict the prince Siddhartha and motifs such as a throne or a dhammachakra to represent him after his enlightenment. These later representations, dating to a second phase of construction in the first century CE, also show a stylistic similarity with sculptures at Karle. During a final phase in the third century CE, the enlightened Buddha was frequently represented as a human figure wearing long, flowing robes; his hair is depicted with semicircles, a feature that appears to have originated in Mathura in the late second century CE. These figures are closely related to the Standing Buddhas at Nagarjunakonda.

A fragmentary sculpture of a yakshi figure, attributed to the second century BCE, has been studied to understand the sculptural style of the Amaravati school. Discovered during excavations at the site of the stupa, this figure appeared superficially similar to yakshi sculptures from the stupa at Bharhut, owing to some similarities in the carving technique. However, the figure from Amaravati, though developed from abstract, cubic shapes, displays a greater degree of nuance in the contours, which are carved to give a softer, more tactile appearance. The figure is depicted with raised upper eyelids, large earrings and an elaborate necklace with segmented pieces giving the appearance of beads. She wears a ring on her left upper-arm, and multiple bangles on the wrist. The left arm hangs below her waist, and she wears an elaborate belt or girdle decorated with round motifs.

Scholars have suggested that the practice of depicting the Buddha first through symbolic and later through corporeal figures may have emerged in Amaravati independently from similar practices in the northern part of the subcontinent. Amaravati is also unique for the simultaneous presence of both the symbolic and the corporeal form, since while the latter does become more frequent over time, it never completely overtakes the symbolic. Both forms are incorporated into the art of the stupa’s railings.

As of writing, fragments from the pillars and railings of Amaravati stupa are divided between the Archaeological Museum in Amaravati, the National Museum in Delhi and the British Museum in London.