Background <p>Family planning is a foundational component of reproductive health that empowers individuals to make informed decisions about childbearing. In Afghanistan, where maternal mortality remains critically high and contraceptive prevalence is low, understanding family planning dynamics is essential for improving reproductive outcomes. This study assessed knowledge, attitudes, and contraceptive use among married women attending a major maternity hospital in Kabul.</p> Methods <p>A cross-sectional analytical study was conducted among 356 married women attending Rabia Balkhi Maternity Hospital in Kabul, Afghanistan, from October 2024 to March 2025. Participants were selected using convenience sampling. Data were collected through face-to-face interviews using a structured, validated questionnaire. Descriptive statistics and chi-square tests were employed for analysis using SPSS version 26. Statistical significance was set at <i>p</i> &lt;.05.</p> Results <p>Out of 356 women, 86.2% had heard of family planning methods. Overall, 77.8% demonstrated good knowledge, and 22.2% demonstrated poor knowledge. Healthcare providers were the primary information source (75.0%), followed by family or friends (46.1%). Regarding attitudes, 84.3% held positive attitudes toward family planning, while 15.7% exhibited negative attitudes. The majority (86.5%) considered family planning important for family well-being. Ever-use <b>of contraceptives</b> was reported by 79.2%, with 72.5% currently using a method. Combined oral contraceptives (COCs) (21.5%) and depot medroxyprogesterone acetate intramuscular injectable (DMPA-IM) (21.4%) were the most commonly used methods. Key barriers to use included husband disapproval (9.6%), lack of knowledge (5.3%), and religious/cultural beliefs (4.8%). Side effects (17.1%) and desire for pregnancy (25.8%) were the primary reasons for discontinuation. Strong positive associations were observed between knowledge and attitude (<i>p</i> &lt;.001), knowledge and practice (<i>p</i> &lt;.001), and attitude and practice (<i>p</i> &lt;.001). Multivariate logistic regression revealed that higher education (AOR = 3.42, 95% CI: 1.87–6.25, <i>p</i> &lt;.001), husband’s supportive attitude (AOR = 2.89, 95% CI: 1.65–5.06, <i>p</i> &lt;.001), and higher household income (AOR = 2.31, 95% CI: 1.34–3.98, <i>p</i> =.002) were significant independent predictors of current contraceptive use.</p> Conclusion <p>Among married women attending this hospital, most demonstrated good knowledge (77.8%), positive attitudes (84.3%), and current contraceptive use (72.5%). Significant barriers, including husband disapproval, side effect concerns, and access challenges, continue to impede optimal contraceptive use. Strengthening provider counseling, expanding media campaigns, engaging religious leaders and husbands, and improving service delivery are essential to enhance family planning uptake and contribute to reduced maternal mortality in Afghanistan.</p>