  If the massive neutrinos are Majorana particles, neutrinoless double beta
($0\nu\beta\beta$) decay experiments are not enough to determine the Majorana
phases. We carry out a systematic study of CP violation in
neutrino-antineutrino oscillations. In these processes, CP-conserving parts
involve six independent $0\nu\beta\beta$-like mass terms $\langle
m\rangle_{\alpha\beta}$ and CP-violating parts are associated with nine
independent Jarlskog-like parameters ${\cal V}^{ij}_{\alpha\beta}$ (for
$\alpha, \beta = e, \mu, \tau$ and $i, j = 1, 2,3$). With the help of current
neutrino oscillation data, we illustrate the salient features of six
independent CP-violating asymmetries between $\nu_\alpha \to \bar{\nu}_\beta$
and $\bar{\nu}_\alpha \to \nu_\beta$ oscillations.
