Phytochemical constituents are important in the determination of plant activities. Their presence in medicinal plants gives their therapeutic values. These phytoconstituents possesses pharmacological activities that include antimicrobial, antioxidant, anti-inflammatory, analgesics, anti-diabetic, anti-hypertensive, antidiarrheal and several other activities. These activities can be determined by the identification of the phytochemicals present in medicinal plants. Petivera alliaceae L. is one of the medicinal plants in the family of phtytolaccaceae used traditionally as an antirheumatic, analgesics, antimicrobial, anticancer and immunomodulators. It is believed to possess rich phytoconstituents especially sulphur containing a broad-spectrum antimicrobial activity. Although the root extracts is been explored but there are limited publication to its root fractions. Therefore, the study is aimed at screening phytochemicals present in the fractions and volatile oil of the root parts of P. alliaceae using qualitative tests and Gas Chromatography–Mass Spectrometry (GC–MS) analysis. Fresh root parts of Petivera allliaceae plant were collected and air-dried. The dried root parts was macerated in absolute methanol for 72 h. The solution was extracted and dried. The dried root methanol extract was partitioned into n-hexane (PAH) and methanol fractions (PAM), while volatile oil (PAO) was extracted using Clevenger-type hydrodistillation method. The result shows that alkaloids, saponins and flavonoids were present while cardiac glycosides, phenol, terpenoids and anthraqunione glycosides were absent in both fractions. The GC–MS analysis identified 18 compounds in PAH, 19 compounds in PAM and 28 compounds in PAO. The fractions and volatile oils of P. alliaceae roots are rich in phytochemical constituents and compounds should be isolated from the fractions and explored for their potentials.