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The foraging activity of Mesobuthus gibbosus was studied and analysed over 290 field samplings in Koufonisi island (central Aegean) and Crete (south Aegean) during the period of maximal activity of the species. The results showed that on both islands males and juveniles searched for prey mainly relatively near or far from their burrows ("sit-and-wait’’ strategy), whereas females foraged comparatively more than males and juveniles at the entrances of their burrows ("doorkeeping’’ strategy). Throughout the study, there was no evidence of two or more individuals foraging together. Re-emergence time after digestion lasts probably more than one month, because no individual was observed foraging twice in the 30 consecutive days of the study period. The individuals that followed the sit-and-wait strategy were larger in size compared to those of the same sex or age-class that used the doorkeeping strategy. The diet of the species was wide, including representatives of eight arthropod orders on Koufonisi and seven on Crete. Stinging was selective and prey selection was based on the age-class of the predator and the size of the prey compared to the size of the predator. The success of sit-and-wait foraging individuals was much more dependent on abiotic factors compared to scorpions using the doorkeeping strategy. Moon phase, air and soil temperature and air relative humidity were the abiotic factors which mainly influenced the foraging activity of these generally non-cannibalistic opportunistic ambush predators on both islands.