The prevalence of unmet need for family planning is a primary justific
ation for family planning programs, but the causes of unmet need have
not been much explored. This article investigates four explanations fo
r unmet need: (1) as an artifact of inaccurate measurement of fertilit
y preferences and contraceptive practice; (2) as a reflection of weakl
y held fertility preferences; (3) as a result of women's perceiving th
emselves to be at low risk of conceiving; (4) as due to excessive cost
s of contraception. The explanations are examined using quantitative a
nd qualitative data collected in 1993 from currently married women and
their husbands in two provinces in the Philippines. The results indic
ate that the preference-behavior discrepancy commonly termed ''unmet n
eed'' is not an artifact of survey measurement. The most important fac
tors accounting for this discrepancy are the strength of women's repro
ductive preferences, husbands' fertility preferences, and the perceive
d detrimental side effects of contraception. Inaccessible family plann
ing services appear to carry little weight in this setting. Modificati
on of services to make them more attentive to other obstacles to contr
aceptive use would improve their effectiveness in reducing unmet need.