||Past intra-urban mobility studies have shown that the decision to seek a new residence is generated by a multiplicity of push and pull factors interacting in a complex manner to influence the “place utility” derived by a household. The household is likely to initiate a move to an alternative site, if the place utility offered is greater than that of its present residence (Wolpert 1965, Brown & Longbrake 1969 & 1970). This research paper examines the overall mobility behaviour of public housing residents. As of 1998, some 86% of the population stay in about 833,814 public housing units completed by the Housing Development Board (HDB) since its establishment in 1960. About 90% of public housing dwellers now own the flat they live in. These households can decide to stay or to move. If the decision is to move, the household could make an intra-HDB move to a larger or smaller HDB flat, or shift from HDB to private housing. Based on a primary micro-data set of about 3,800 households, this paper examines the patterns of residential mobility in terms of their spatial tendency and the choice of the types of property moved to. It also seeks to determine the likelihood that a household would move, given different HDB type, by appealing to the conditional probit choice models. The study revealed interesting results in the mobility behaviour of the HDB households. Upgrading to better housing and home-ownership/investment stand out as the main underlying forces that motivate residential mobility. Households prefer dwelling with close proximity first to shopping facilities, then workplace, good schools and, lastly, relatives. Indeed, future bequest motive scores as a more important reason than even prestige reason for motivating households’ move to their new residence. This indicates that households have strong bequest motive. In considering factors influencing buying decision of their residence, households place great importance on price, location and unit characteristics. In line with observations of mobility patterns in the West (Simmons 1968, Adams 1969, Clark 1971, Johnston 1972), it is noted that distinct sectoral bias similarly exists in the mobility patterns of the households, as they move within the same region where their previous dwelling is located. Compared to the United States, Singaporeans are relatively less mobile. On average, households are likely to make a move once every 8 to 9 years. In the U.S., 60 to 70 percent of the entire population move at least once within a five-year period (Simmons, 1968). The study also found that there is a greater proportion of households enjoying an improvement in their housing tenure (from rent/living with relatives or friends to home-ownership) as well as in their housing status (upgrading from a lower housing category to better quality housing category) when they made a move. In examining the overall mobility of HDB households using the probit econometric model, we note that households that live outside the North region, particularly those in the North-East, and households that have higher income and heads in the professional occupations are more likely to make a move out of a HDB residence. As for the impact of life cycle variables, age appears to exert a negative effect on the propensity to move. Older household heads tend to exhibit the inertia to move. However, household size does not seem to affect mobility tendency. When intra-HDB mobility is analysed, the 3-room HDB flat dwellers are surprisingly the most mobile compared to households staying in larger flats, followed by the 4-room flat dwellers. They have the greater likelihood of making an intra-HDB move, upgrading to larger flats within public housing, especially when the households have dual income sources from working spouses. The executive/HUDC flat dwellers are more likely than other households to move to private housing than make an intra-HDB move. This is followed by the 5-room HDB flat dwellers. It is interesting to note that if the 5-room HDB flat-dwellers were to make an intra-HDB mobility, they are more likely to opt for the following types of housing in decreasing order: first, for a lateral move to a similar 5-room flat; next, to downgrade to 4-room flats; and lastly, to upgrade to the executive or HUDC flats.