This study examines the profitability of airlines pertaining to global airline strategic alliances for a period of eleven years, centred on the year airlines joined their alliances. Overall, the results obtained show that airlines which joined Oneworld, SkyTeam or Star Alliance lost relative performance and, thus, profitability after joining their alliances, even when they had been doing exceptionally well before joining. In contrast, a group of airlines not in an alliance remained profitable throughout a comparable period of time, achieving a positive relative performance at the end of the eleven-year period. As a similar pattern of profitability occurred for each group of allied airlines, these results suggesting that the benefits of joining an alliance may not necessarily translate into profitability. In fact, airlines might have been better off by themselves than they did by joining an alliance, at least in regards to net returns alone.