Context :

Aims : We compare the mass distribution of central stars of planetary nebulae ( CSPN ) with those of their progeny , white dwarfs ( WD ) .

Methods : We use a dynamical method to measure masses with an uncertainty of 0.02 M _ { \odot } .

Results : The CSPN mass distribution is sharply peaked at 0.61 M _ { \odot } .
The WD distribution peaks at lower masses ( 0.58 M _ { \odot } ) and shows a much broader range of masses .
Some of the difference can be explained if the early post-AGB evolution is faster than predicted by the Blöcker tracks .
Between 30 and 50 per cent of WD may avoid the PN phase because of too low mass .
However , the discrepancy can not be fully resolved and WD mass distributions may have been broadened by observational or model uncertainties .

Conclusions :