An experimental method was used to study the thermal-fluid characteristics of plate-fin heat sinks cooled by a piezoelectric fan. The fan configuration, the fan location, and the heat sink dimensions were evaluated in terms of effects on thermal resistance. The experimental results show that, when the piezoelectric fan is vertical, thermal performance is the best with the tip of the fan blade at the center of the heat sink. When the piezoelectric fan is horizontal, thermal performance is the best with the tip of the fan blade at the front edge of the heat sink. In most cases, a vertical piezoelectric fan performs best with low fin heights. When the piezoelectric fan is horizontal, the thermal performance enhances as the fin height increases for three-fin heat sinks. For two-fin heat sinks, however, the correlation with fin height depends on the fin width. Heat transfer efficiency does not increase with fin width when the piezoelectric fan is vertical. However, thermal resistance usually decreases with fin width when the piezoelectric fan is horizontal. (C) 2012 Elsevier Ltd. All rights reserved.