Positron lifetime spectra were measured in solid and liquid phases of 2-norbornylene. No accumulation of excess electrons in the brittle phase was observed. The vacancy activation enthalpy in plastic phase was found equal (0.13 +/- 0.02) eV. The temperature dependence of positronium lifetime in the bulk deviates from expectations of two-state model; it can be explained by an assumption that some of positronium atoms are created directly in vacancies (not transferred from the bulk). The macroscopic surface tension of liquid norbornylene at 330 K is estimated as (23.1-26.6) mN/m. (C) 2016 Elsevier B.V. All rights reserved.