The genus Piper, belonging to the Piperaceae family, includes over 2,000 species, many of which are widely recognized for their significant economic and medicinal importance. In recent years, research on Piper species has advanced, with numerous studies highlighting their intriguing pharmacological properties. The enzyme inhibitory effects of plant-derived compounds play a significant role in addressing various diseases, including neurodegenerative disorders, hyperpigmentation, and diabetes. This study evaluates the acetylcholinesterase (AChE), tyrosinase, and α-glucosidase inhibitory activities of ethanolic leaf extracts from five Malaysian Piper species: Piper rostratum, P. frustratum, P. penangense, P. baccatum, and P. crassipes. The extracts demonstrated varying degrees of enzyme inhibition, with P. baccatum exhibiting the strongest AChE inhibition (IC50 value of 21.5 μg·mL-1), P. frustratum the highest tyrosinase inhibition (IC50 value of 12.6 μg·mL-1), and P. rostratum the most potent α-glucosidase inhibition (IC50 value of 12.1 μg·mL-1). These activities are attributed to the bioactive phytochemicals, including alkaloids, flavonoids, and phenolic compounds, known for their enzyme-inhibitory and antioxidant properties. This is the first study to report these specific activities for these Piper species, highlighting their potential as natural therapeutic agents and offering insights into their medicinal applications for neuroprotection, skin health, and diabetes management.