| Certainly. What is so cool about fretless is that the instrument setup doesn't have to be 99.9% dialed in (particularly string length) to play it in tune, unlike a fretted bass. If the overtones are in alignment across the strings, your ear can get everything else in tune.
Occasionally on a fretted bass I've had a string go a little sharp or flat over the course of a set. You then have to try to tune on the fly or avoid the string or bend the notes sharp or pressure the notes flat (a little pressure on the back of the neck can drop the pitch a few cents). On fretless this is not a problem because you just correct the notes on the fly using your ear... except for open strings or natural harmonics. | 
