Background
The GAP between the knowledge of contraception and its actual practice is well recognized in the literature of family welfare studies. The present study assessed the relation between the level of knowledge and practice of contraception among the women and sought to explore the reasons behind the Knowledge, Attitude, and Practice - GAP (KAP GAP) regarding contraceptive users in six cities of Uttar Pradesh.

Method
Present analysis based on 17,643 currently married women aged 15 to 49. A Bivariate analysis (χ2 test) and a multivariable logistic regression were performed for the study.

Result
The highest percentages of respondents (women) were in the age group 35–49 (40–45 %) in all the districts considered. Knowledge of contraceptives was almost universal; tubal ligation and pill were the commonly known methods. Information about the contraceptive methods was mostly obtained through the husband. In the present study, there was a highly significant association (p < 0.01) of age group, educational status of respondents, the number of living children, the wealth of the respondent, media exposure and husband’s education with the variable KAP GAP for all six cities. Health concern issues in all the districts were the most prominent reason for not using contraception.

Conclusion
There differences in the socioeconomic and demographic factors exist, which lead to KAP GAP in the family planning (FP) usages. Therefore, in designing effective family planning programme, there is a need to understand the various factors which influence the practice of contraception.