β-tubulin is the target of various antitubulin agents used in the treatment of cancer. After β tubulin was shown to confer resistance to antitubulin agents in established cell lines, several studies have investigated the DNA sequence of this compound in clinical samples. However, these findings are highly controversial, since sequencing experiments showed that the original clinical observation of mutations in the gene resulted from inclusion of non-functional β-tubulin pseudogenes. At least nine such pseudogenes are known, and all share substantial sequence homology with the functional gene. Subsequent studies have concluded that β-tubulin mutations in clinical samples are rare, and unlikely to contribute to drug resistance. Here, we overview the β-tubulin gene family and summarise the results of studies done comparing β-tubulin mutations with antitubulin drug resistance.