Purpose: The purpose of this study was to examine family planning Knowledge, Attitude and Practice (KAP) among women of reproductive age in Nimule Payam, South Sudan. Method: The study used a descriptive cross-sectional design and quantitative approach to explore family planning knowledge, attitude and practice among women of reproductive age in Nimule Payam. The study population consisted of 6,621 women of reproductive age in the Bomas of Anzara (1,930), Jalei(,1521), Olikwi (1,536) and Nimule Central (1,634). A sample size of 342 was determined from the population using the formulae of Leslie. Stratified simple random sampling was employed through a researcher administered structured questionnaire to collect data from the respondents. The data was cleaned, coded and analyzed using EPI-INFO version 7 to generate descriptive statistics and the results were presented in tables. Results: The study revealed that women of reproductive age in Nimule Payam had high 273 (79.82%) level of family planning knowledge, good 233 (68%) family planning practices and positive attitude towards family planning. The positive attitude towards family planning was because majority 270 (78.97%) believed family planning was safe to use, could not cause infertility 252 (73.82%), cancer 264 (76.93%) and future abortion 251 (73.36%). The respondents also generally agreed that 319 (93.07%) family planning could prevent unwanted pregnancy. However, the majority of the respondents acknowledged that the practice of family planning was against their God/Allah 268 (78.31%) and culture 229 (67.03%). Unique contribution to theory, practice and policy: The study found that women of reproductive age in Nimule Payam had a high level of family planning knowledge, a fairly positive attitude with a moderate number practicing family planning methods. Increased sensitization of the respondents and their partners on family planning is required to improve their attitude and practice. Future studies should focus on the factors influencing the Knowledge, Attitude and Practice of family planning methods among women of reproductive age in Nimule Payam.