This article presents a mini medical technology evaluation of three less invasive monitoring techniques for monitoring cardiac output, CardioQ, ECOM and PiCCO, with focus on validation, usability and costs in intensive care. In conclusion, when identifying patients with low cardiac output, we suggest starting with simple screening tools (e.g. CardioQ or central venous O2 saturation), and when in doubt, upgrade to better validated, yet more time-consuming techniques (e.g. PiCCO using thermodilution). Also consults should be made to other intensive care units in terms of the practical implementation of the monitors.