Background: Unmet need for family planning, refers to the condition in which there is the desire to avoid or post–pone child bearing, without the use of any means of contraception. Objectives: The objective of the study was to determine the prevalence of “unmet need for FP” and its socio–demographic determinants among married reproductive age group women residing in rural area of district Jhajjar. Materials and Methods: a community–based cross–sectional study among married women of the reproductive age group, between 15 and 49 years. The sample size required was 900. The simple random sampling method was adopted. Results: total unmet need was 37%. 15% for spacing & 22% for limiting. Mother’s age, education, contraceptive knowledge, desired family size, age at 1st child birth, male participation are found to be significant. Conclusion: high prevalence of unmet need for Family planning which is more for limiting but is being satisfied. However, need for spacing is less but is least satisfied