We present a noninvasive full-field method--laser speckle imaging (LSI)--for measuring the regional mesenteric blood flow without scanning. A system of LSI was designed and validated in a model experiment. Dynamics of regional blood flow in the rat mesentery under the influence of noradrenaline were monitored by this method. Spatial and temporal characteristics of the mesenteric blood-flow response were achieved with high resolution. These suggested that LSI might provide a new approach to microcirculation studies.