Acetylcholinesterase (AChE) inhibitors are currently the most widely prescribed drugs for Alzheimer's disease. The high potential of indole compounds in medicinal chemistry led us to discover a novel series of fluoroindole compounds. The synthesis and pharmacological analysis of the difluoropyrido[4,3-b]indoles 11-34 are described. Compounds 11-34 were tested for AChE inhibition activity using a rat brain homogenate. Compounds 25-29 display a promising in vitro profile with an IC50 value range of 46-51.6nM and show significant protective effect on scopolamine-induced amnesia. The present data indicate that compounds 25-29 may represent attractive potent molecules for the treatment of Alzheimer's disease.