Medicinal plants are rich source of phytochemical constitutes and can be used to treat many human diseases. Infectious diseases have always been a major source of concern. Globally, the medicinal plant Achillea wilhelmsii locally known as Bohe Madran is extensively dispersed and widely used as traditional medicine. The aim of this present work is to investigate phytochemical constituents and antimicrobial, antioxidant, and anti-inflammatory properties of the whole plant ethanolic extract of Achillea santolinoides subsp. wilhelmsii (WEEAW) from Balochistan region. The total phenolic content was
14.81
±
0.18
mg GAE/g of the extract whereas the total flavonoid content was
12.27
±
0.12
mg QE/g of the extract. The antioxidant ability of the extract was analyzed by DPPH (2,2-diphenyl-1-picryl-hydrazyl) scavenging assay and FRAP (ferric reducing antioxidant power) assay in terms of concentration having 50% inhibition (IC50). Results showed that IC50 value for DPPH% inhibition was
0.367
±
0.82
mg/mL while FRAP assay represented with IC50 value of
0.485
±
1.26
mg/mL. In antileishmanial bioassay, the extract was analyzed against Leishmania major and showed good activity with IC50 value of
7.02
±
0.83
mg/mL. Antibacterial assay revealed that Staphylococcus aureus was highly sensitive with the diameter of inhibition zone (
21.61
±
1.09
mm) followed by Salmonella typhi (
17.32
±
0.15
mm), Pseudomonas aeruginosa (
16.41
±
0.63
mm), and Escherichia coli (
15.30
±
1.17
mm) while Klebsiella pneumoniae showed minimum inhibition (
14.13
±
0.49
mm). Antifungal activity was tested against Aspergillus flavus with 89% of inhibition zone and 77% against Mucor mucedo and Aspergillus niger with 74% of inhibition zone. The anti-inflammatory assay was carried out by inhibiting protein denaturation, proteinase inhibitory activity, and heat-induced hemolysis. The IC50 value for protein denaturation was
6.67
±
1.25
mg/mL, proteinase inhibitory with IC50 value of
4.12
±
0.69
mg/mL, and heat-induced hemolysis assay with IC50 value
4.53
±
0.82
mg/mL by comparing to the standard drug aspirin having IC50 value
1.85
±
0.54
mg/mL. Results of the current work showed that whole plant ethanolic extract of Achillea wilhelmsii exhibited substantial anti-inflammatory action, thus can be utilized as a traditional treatment. Furthermore, overall finding of this research suggested that the antioxidant potential of the plant aids to prevent free radical damage and reduce the incidence of chronic disease. More research is needed to find out more active compounds present in the extract that are responsible for their pharmacological effects.