BACKGROUND Acetylcholinesterase (AChE) and cholinergic receptors have an important role in the immune system and angiogenesis. This work evaluated the effects of isopropyl methylphosphonofluoridate (IMPF), an irreversible inhibitor of AChE, on tumor growth and selected parameters associated with tumor angiogenesis. MATERIAL AND METHODS Experiments were performed on male BALB/c mice exposed to IMPF (study group) or saline buffer (control group) and inoculated with L-1 sarcoma; the number of new blood vessels (TIA test) and the level of αvβ3 integrin (131I-MAb-antiβ3 assay) were analyzed at seven, 14, or 21 days after implantation of the tumor cells. RESULTS The IMPF poisoning affected tumor angiogenesis (TIA test). There was a statistically significant increase in the number of newly forming blood vessels in the group subjected to IMPF and inoculated with tumor cells. CONCLUSIONS This study showed that IMPF had a significant effect on the regulation of lymphocyte-induced angiogenesis and the modulation of angiogenic and pro-inflammatory cytokines secretion. The observed effects suggest involvement of neuronal and/or non-neuronal cholinergic signaling pathway.