A survey on the importance of Lacerta bilineata as host of Ixodes ricinus was conducted in Northern Italy over a three-year period. A total of 202 western green lizards were captured and a total of 2349 ticks were collected. All ticks were identified as I. ricinus; 53.2% and 46.7% were at the larval and nymphal stages, respectively. Tick number and prevalence were higher in males than in females, especially from April to June during the host breeding period. The level of tick infestation increased with lizard age and size. The number of ticks collected on adult lizards peaked in June and in August. Infestation levels appear to be related to lizard activity patterns and behaviour. Tick number and prevalence also varied in relation to host habitat, infestation being higher in lizards from areas with hard vegetation cover.