Experiments have been conducted to analyze the flow and pressure distribution in a plate heat exchanger by measuring local port pressure distribution in a commercial plate heat exchanger. Flow rate in channel and channel pressure drops are evaluated by measuring the pressure inside the inlet and exit ports at different locations for different port dimensions. In these experiments, the measurement of pressure is done without disturbing the fluid flow inside the port. This technique also offers the option of manipulating port size without changing the plate characteristics. Direct experimental measurement provides the scope for eliminating other effects, such as gasket, end losses, and improper wetting of channels from the flow maldistribution effect. The measurements indicate the existence of non-uniform flow distribution that increases with flow rate and decreases with port diameter. Results clearly show that it is important to consider the flow maldistribution for better design of plate heat exchangers.