The effectiveness of a manufacturing product produced depends on whether the specified standards by the management / production engineers are met or not. It is possible that a process will be stable but will not meet the specification set by the production engineer or management. In order to determine whether a process meets the specification of the process engineer or management, process capability indices (PCIs) are often used. This study is aimed at evaluating the capability and the percentage of nonconforming unit of a manufacturing process. Data on two quality characteristics were extracted from the records of Evans Medical PLC, Agbara, Nigeria. The process capability indices were used to determine the capability of the process and the percent non-conforming was used to check the amount of the process that does not meet the required standard. The obtained results reflect the amount of the products produced during the period of study that do not conform to specification and the gain of testing for the normality assumption as reflected in the parts per million defects for the process data. The confidence interval derived for the process indices can be used to improve the capability of the process.