Adhesive composition comprises a polyfarnesene and a tackifier. The polyfarnesene can be a farnesene homopolymer derived from a farnesene (e.g., .alpha.-farnesene or .beta.-farnesene) or a farnesene interpolymer derived from a farnesene and at least a vinyl monomer. In some embodiments, the at least one vinyl monomer is ethylene, an .alpha.-olefin such as styrene, or a substituted or unsubstituted vinyl halide, vinyl ether, acrylonitrile, acrylic ester, methacrylic ester, acrylamide or methacrylamide, or a combination thereof. The composition disclosed herein can be used as a hot melt adhesive, a pressure sensitive adhesive or the like.