Hemiparasitic plants commonly known as mistletoe (muérdago in Spanish) in the families Santalaceae and Loranthaceae are common in various kinds of plants or trees, and many hemiparasitic plants are used for medicinal purposes in various parts of the world. The objective of the present work, carried out in Psittacanthus linearis (suelda con suelda), a representative species in the seasonally dry forest (SDF) from the north of Perú, was to study aspects of in vitro tissue culture, carry out preliminary phytochemical analysis, and assess antibacterial activity. Seeds of individuals of P. linearis, which used Prosopis pallida (algarrobo) as host plant, were collected and used to induce in vitro seed germination, clonal propagation, callus induction and organogenesis. Stems, leaves and fruits of individuals of P. linearis were dried, powdered, and subjected to ethanol extraction. Posteriorly the extract was first recovered with ethanol and the remnant with chloroform, which formed the ethanolic and chloroformic fraction. A preliminary phytochemical screening was performed and preliminary antibacterial studies with Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were carried out and their results are discussed. This is the first report about in vitro tissue culture, phytochemical analysis and antibacterial activity of P. linearis. The results may have important implications for understanding physiological and biochemical interactions between host and hemiparasitic species as well as P. linearis with P. pallida and other SDF species.