Multiple input/multiple output (MIMO) radar system performance benefits from the capability to simultaneously transmit and receive multiple orthogonal waveforms. For pulse radars fitting orthogonal waveforms have been developed. These waveforms are however not necessarily suitable for frequency-modulated continuous-wave (FMCW) radar. The major benefit of the FMCW radar principle is that the bandwidth of the beat signal is generally much smaller than the signal bandwidth, relaxing sampling requirements. Preferably, this benefit should be preserved when applying orthogonal waveforms in an FMCW MIMO radar configuration. In this paper, orthogonal waveforms compatible with the FMCW radar principle will be discussed and tested by experiment or simulation.