The effects of four concentrations of clove oil (150, 300, 450 and 600 mg L-1) as ananaesthetic substance at three temperature levels (10, 15 and 20 degrees C) and three fish size (as weight) groups (57.0 +/- 11.3, 103.0 +/- 11.9 and 457.0 +/- 89.8 g) on induction and recovery times in turbot (Psetta maxima) were investigated in this study. The fish were individually exposed to each clove oil bath in 10, 20 or 50L buckets with respect to fish size and were recovered in a 500-L tank with running seawater. Temperature, fish size and clove oil concentrations were found to have significant effects on induction and recovery times in turbot (P<0.01). Induction and recovery times were both less than half when the temperature was increased from 10 to 20 degrees C (P<0.01). The duration to reach surgical anaesthesia and recovery times of small size turbot varied in relation to temperature, but were generally shorter than big size turbot (P<0.01). Overall, the increase of clove oil concentration from 150 to 600 mg L-1 decreased the induction time by a factor of 2.3 but on the contrary, prolonged the full recovery time by a factor of 1.92. The surgicalanesthesia was attained in all the groups under 4.45 min at 150 mg L-1 or even under 2 min at 600 mg L-1 clove oil concentration. However, the time of recovery ranged from 4.32 min (150 mg L-1) to 8.29 min (600 mg L-1). Based on our results, the clove oil concentrations around 180-220 mg L-1 appeared to be adequate to be used for fast anaesthesia and relatively short recovery time for turbot. Mean effective concentration (EC50) of clove oil was calculated as 190.00 +/- 10.34 mg L-1 with 95% confidence limits for overall three temperature and fish sizes. This study has demonstrated that clove oil can be safely and effectively used in the anaesthesia of turbot.