BACKGROUND Increasing access to family planning helps to ensure the reproductive right, decrease unintended pregnancy, improve the health and nutritional status of children, reduction of maternal mortality, and enhance longer birth spacing. However, there is continually low utilization of long acting and permanent contraceptive methods among low and middle-income countries. This study aimed to assess the utilization of long acting and permanent contraceptive methods (LAPMs) and associated factors among women of reproductive age in the West Guji Zone, Ethiopia. METHODS An institution-based cross-sectional study was carried out among 507 women of reproductive age in the West Guji Zone, Southwest Ethiopia from April 15 to May 15, 2018. Data were collected by a structured, pretested, and interview-based questionnaire with open ended and closed ended questionnaire, then entered, and analyzed by SPSS Version 20. Bivariable and multivariate logistic regression analyses were carried out. A 95% confidence interval (CI) AND P-value < 0.05 was considered to declare statistically significant variables. RESULTS The current utilization of LAPMs at West Guji zone among the reproductive-aged group was found to be 51.1%. More than the median of participants had negative altitude (72.4%) and poor knowledge (57%) towards the LAPMs. Educational status of women, the number of alive children, acceptance of utilization of LAPMs, how treated by other staff, and waiting time during service delivery are significant determinant factors of LAPMs. CONCLUSIONS Overall, more than half of women had a negative attitude and poor knowledge of LAPMs. Educational status of women, the number of alive children, acceptance of utilization of LAPMs, how treated by other staff, and waiting time during service delivery were factors affecting utilization of LAPMs. Therefore, sustained, and appropriate information on LAPMs should be provided to raise knowledge and build the attitude of women and the community. Treating the clients with respect, reducing the waiting time, and collaborative work with health extension worker will enhance utilization of LAPMs.