Convective oxygen transport by microvessels depends on several parameters, including red blood cell flux and oxygen saturation. We demonstrate the use of intravital microscopy techniques to measure hemoglobin saturations, red blood cell fluxes and velocities, and microvessel cross-sectional areas in regions of microvascular networks containing multiple vessels. With these methods, data can be obtained at high spatial and temporal resolution and correlations between oxygen transport and hemodynamic parameters can be assessed. In vivo data are presented for a mouse mammary adenocarcinoma grown in a dorsal skinfold window chamber model.