AbstractDevelopment ofNeostrongylus linearislarvae was studied in the snail intermediate hostsOestophora(Oestophora)barbula, Oestophorella buvinieri, Cepaea nemoralisandHelix(Cryptomphalus)aspersa. The molluscs of each species, all adults, were divided into groups of 40 for infection purposes. The infection doses for the first two snail species were 90 and 50 first stage larvae (L1) ofN. linearis, respectively. ForC. nemoralistwo batches were tested: one with 200 L1 kept at 19°C and the other with 250 L1 at a temperature of 21°C. The same was done withHelix(C.)aspersawith 200 L1 at a temperature of 21°C, on the one hand and 300 L1 at 24°C on the other. One or two molluscs of each species were killed in series from the 6th day post-infection (p.i.) until the 44th. Percentage values for total larvae (1, 2 and 3) and L3 were higher with the lower dose forC. nemoralis, whilst the same was true with the higher dose inHelix(C.)aspersa. In both cases, the higher temperature appeared to contribute to cycle acceleration. Using one way analysis of variance, statistically significant differences were detected between the species of molluscs tested concerning percentages of L1 which penetrated, total larvae and L3. According to our results, the decreasing order of susceptibility of these species of molluscs as experimental intermediate hosts ofN. linearisis:O. buvinieri,Oestophora(O.)barbula,C. nemoralisandHelix(C.)aspersa. It is the first time thatOestophora(O.)barbulaandOestophorella buvinierihave been named as experimental intermediate hosts ofN. linearis.