As of Census Year 2000, Mandaluyong City has a total population of 278,474, accounting for about 2.8% of the total population of the National Capital Region which is 9,932,560. With an average household size of 4.6, it has a household population of 275,110 which may also be considered as the nighttime population of the city. (see Figure 2.01)

In the absence of published information and studies concerning daytime population in the city, there is a suggestion that having acquired a full level of urbanization, Mandaluyong City follows the trend in Makati City by which daytime population is three (3) to four (4) times its nighttime population. Thus, on the conservative side, daytime population for Mandaluyong City is estimated as (3) (275,110) or 825,318.

Almost everyone in Mandaluyong is Filipino of various ethnic origins (Table 2.02). Even so, the languages generally spoken in the households are Tagalog (96.47%), Bicol (0.40%), Bisaya (0.30%), Ilonggo (0.40%), and Ilocano (0.60%). See Table 2.03

About ninety-one percent (91%) of the residents belong to the Roman Catholic Church, and the remaining nine percent (9%) are distributed among religious denominations like the Iglesia ni Kristo (2%), Evangelicals (1.6%), other Protestants (0.42%), Jehovah’s Witness (0.42%), Aglipayan (0.66%) and others (1.7%).

The spatial distribution of churches of the various religious congregations in the city is shown in Map ~ Places of Worship.

The typical family of Mandaluyong has an average of 4.61 numbers. Of the 59,682 households, 18.82% are headed by women and 81.18% are headed by men. Majority of these households totaling 86.78% are headed by men and women in their prime productive ages between 20 years and 60 years old, while 12-67% have household heads in the elderly age group of 60 years and above. A little over 0.54% of the number of households are headed by the young population 20 years old and below.

A combination of married and widowed individuals accounts for 48.02% of the household population while family members who remain single total 43.46% with female members slightly more than male members at 51.02% and 48.98%, respectively. Others who opted for other forms of family union account for 8.52%. These include individuals that are either divorced, separated, common-law spouses, and those whose marital status are unascertained. (Table 2.05)