Background: Clinical coding is an integral part of health information management (HIM) practice which provides valuable data for healthcare quality evaluation, health resource allocation, health services research, medical billing, public health programming, Case-Mix/DRG funding. The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) is a veritable tool for the effectiveness of clinical coding practices. Objective: This present study determined implementation levels of ICD-10 as well as ICD-10-PCS and clinical coding practices in both public and for-profit hospitals in Nigeria. Methods: We used Chi square (χ2) and Cramer’s V (φc) to assess the level of association between type of workplace and implementations of ICD-10 and clinical coding practices. Statistical significance was set at .05. Result: The study discovered nationwide implementation of ICD-10 (179, 88.2%) and fair adoption of its procedure counterpart (79, 38.9%). Most hospitals in Nigeria especially, for-profit facilities (3, 100%) and tertiary healthcare settings (148, 93.1%) employed HIM professionals (214, 91.5%) to manage their clinical coding processes. Conversely, the study observed that challenges confronting clinical coding processes were enormous. Notable among these were absence of automation (70, 34.5%), lack of political will (51, 48.1%), inadequate clinical coders (153, 74.4%) and suboptimal documentation (186, 91.6). Suggestions to improve clinical coding practices ranges from continuing professional coding education (33, 10.3%) to initiation of Nigerian’s modification of ICD such that ICD-10 will become ICD-10-NGM (1, 0.3%). Conclusion: Most healthcare systems in Nigeria have implemented ICD-10 for coding and classification of diagnoses and procedures and the process is being managed by the right workforce (i.e. HIM professionals) which reassures effectiveness. However, lack of political will, inadequate and unmotivated workforce and suboptimal clinical documentation were among challenges confronting the practice in Nigeria. Therefore, this study suggests advocacy and coding education with a view to modifying the orientation of all stakeholders and to sensitize relevant authorities on the benefits of clinical coding practices in order to maximize its outcome and in effect, improve public health in the country.