Malaria was once endemic in the Osijek region of Croatia and although it has been eradicated, there are still several vector species of the Anopheles maculipennis complex in this area. During an eight-year investigation, using CDC traps with CO2 as an attractant, we collected a total of 3,508 mosquitoes. We determined the dynamics of members of this complex and found that they varied considerably with an average of two generations per season. Cross-correlations indicated that the Spearman's Index between the abundance rate and the water level was the highest 12 and 24 d before traps were set. This suggests that the long-term high water level created better conditions for continuous breeding of mosquitoes, which contributed to a significant increase in abundance rates of all species in the complex.