Hedonism is a way of life, characterised by openness to pleasurable experience. There are many qualms about hedonism. It is rejected on moral grounds and said to be detrimental to long-term happiness. Several mechanisms for this 'paradox of hedonism' have been suggested and telling examples of pleasure seekers ending up in despair have been given. But is that the rule? If so, how much pleasure is too much? An overview of the available knowledge is given in this paper. The relation between hedonism and happiness has been studied at two levels: that of the nation and the individual. At the national level average happiness is correlated with moral acceptance of pleasure and with active leisure. At the individual level it is similarly linked with hedonistic attitudes and also correlated with hedonistic behaviours such as frequent sex and use of stimulants. In most cases the pattern is linearly positive. The relation between happiness and consumption of stimulants follows an inverted U-curve, spoilsports and guzzlers are less happy than modest consumers. Yet these data cannot settle the issue, since the observed relations may be spurious or due to the effects of happiness on hedonism rather than the reverse. Even if we can prove a positive effect of (mild) hedonism on happiness, there is still the question of how that gains balances against a possible loss of health. A solution is to assess the effect of hedonistic living on the number of years lived happily.