The woody vineCelastrus orbiculatus(Celastraceae), Oriental bittersweet, is an alien species that recently has been found to be spreading in Europe. Many aspects of its biology and ecology are still obscure. This study evaluates the distribution and habitats, as well as size and age of stands ofC. orbiculatusin Lithuania. We investigated whether meteorological factors affect radial stem increments and determined seedling recruitment in order to judge the plant’s potential for further spread in Europe. We studied the flower gender ofC. orbiculatusin four populations in Lithuania and found that all sampled individuals were monoecious, although with dominant either functionally female or male flowers. Dendrochronological methods enabled us to reveal the approximate time of the first establishment of populations ofC. orbiculatusin Lithuania. The youngest recorded individual with fruits was determined to be 10 years old. Analysis of radial increments revealed no reliable correlations with meteorological conditions. Therefore, we conclude that climatic conditions in the region are favourable for the growth, reproduction, and invasion of this species.C. orbiculatusproduces viable seeds, successfully reproduces and spreads within and around the established stands. The presence of seedlings and two- to four-year-old saplings in the population confirms constant generative recruitment. Available information on the distribution ofC. orbiculatusin Europe revealed its existence in 13 countries. In total, 58 occurrences of this species have been recorded in Europe so far. We consider that the lag period lasted until 2005 and that the exponential population growth phase has now set in. In Lithuania, the invaded area is quite small (0.51 ha); however, the total estimated invaded area in Europe could be about 250 ha. At the current stage of invasion and distribution in Europe, measures for control, management, and eradication ofC. orbiculatushave a chance of being effective and economically feasible.