Study aim: This study aims to evaluate the effectiveness of an educational intervention program on fertility knowledge, childbearing intention and planned pregnancy rate among 1240 couples referring to premarital counselling centres. Design: This study is a parallel randomised clinical trial with pre-test/post-test design. Settings and conduct: This study will be conducted in five metropolitan cities of Iran with a diverse geographical distribution (Tehran, Mashhad, Ahvaz, Tabriz and Shiraz). Data will be collected by questionnaires at baseline and 3, 12 and 18 months after the intervention in each selected city. Participants will respond to a self-administered demographic characteristics questionnaire, the Cardiff Fertility Knowledge Scale (CFKS), the childbearing intention questionnaire and some questions about their pregnancy (planned/unplanned pregnancy). Given the nature of the intervention, it is not possible to blind participants to researchers involved in providing the intervention and data collection. Participants/Inclusion and exclusion criteria: We plan to recruit new couples (men and women) referring for compulsory premarital counselling. Intervention groups: The intervention group will receive both the typical premarital counselling training and a fertility knowledge package containing virtual (off-line) educational package at two time episodes with an interval of one month. The intervention includes text messages and short films. The control group will receive only typical premarital counselling. Main outcome variables: The primary outcomes are fertility knowledge, childbearing intention and the first planned pregnancy rate (positive pregnancy test).