•Connectedness between major forex currencies and cryptocurrencies is examined.•The quantile cross-spectral approach is utilized.•The connection between cryptocurrencies is not as strong as is believed.•The intragroup dependencies are positive in the lower extreme quantiles.•The intergroup dependencies are negative in the lower extreme quantiles. This paper analyzes the connectedness between forex and cryptocurrencies using the quantile cross-spectral approach. The sample covers six forex and six cryptocurrencies over the period of September 2015–December 2017. Compared with the results obtained from standard correlations and DMCA, the quantile cross-spectral approach provides richer information on the dependence structure across different quantiles and frequencies. The results show that there are some significant negative dependencies between forex and cryptocurrencies from both the short- and long-term perspectives; thus, it is worth diversifying between these two asset groups. Moreover, the connection between cryptocurrencies is not as strong as is widely believed.