The objective of this thesis is to gain insight into the broad asset class decisions of households, in comparison to saving and investment theory. Investment theory prescribes that asset portfolios should be as highly diversified as possible to reduce unsystematic risk. Over the long term, this should provide the highest possible returns given the minimal risk chosen to be undertaken. Savings theory on the other hand, predicts that households choose assets in accordance with life-cycle stages as well as to satisfy some motives for saving like retirement and to bequest wealth to heirs. The household finance literature shows that the financial decisions of households are somewhat more dependent on life-cycle stages and demographic and socioeconomic characteristics than investment theory. In Australia, there is a distinct lack of empirical literature on the financial decisions of households generally, and on portfolio construction decisions more specifically. Accordingly, this thesis uses a high quality longitudinal survey of Australian households, the Household, Income, and Labour Dynamics in Australia (HILDA) Survey, to investigate three areas of asset portfolio decision-making. The HILDA Survey began in 2001 and aims to track 7,682 households comprising 19,914 individuals throughout their lives, and includes broad social and economic topics, including attitudinal questions on financial risk-taking. In addition, the less-frequent wealth modules in HILDA (in 2002, 2006 and 2010) include additional questions relating to household investment in a number of key assets, including the family home and other property, superannuation, equity and cash investments, business assets, bank accounts, life insurance, trust funds, and collectables.