Studies on development of a sampling strategy for the complex species of leafhoppers, Asymmetrasca decedens (Paoli) and Empoasca decipiens Paoli within glabrous cotton Cukurova 1518 were done in Adana province, Turkey during 2003-2005. The nymphs showed aggregated distribution pattern, but adults regularly distributed on cotton plants with different ages. The leafhoppers were aggregated on the lower leaves of plants with 9 main stem node (MSN). As plants grew to 12 MSN, they typically moved upwards away from damaged lower leaves to less damaged leaves in the middle stratum. The best MSN leaf to sample nymphs or adults of the leafhoppers was the 8th from the apex, when plants had 9-15 MSN. The population density of leafhoppers strongly affected the numbers of leaf samples required. Numbers of samples needed to estimate the densities with 3, 5, and 10 nymphs per leaf sample at the 20% precision level in 0.3 ha area were 33, 12, and 3, respectively. Population densities of the leafhoppers were significantly lower in the early morning (0530-0700 or 0730-0800 h) than those found in other times of a day. This study suggests that leafhoppers could be sample in any time of a day after 0800 h, preferably 1800-1900 h, in June-July period in the Mediterranean region.