The study investigated the performance of individual classification societies in the Abuja Memorandum of Understanding (MoU) on Port States Control (PSC) with a view to providing empirical evidence and information on the levels and rates of change of inspected ships, detained ships, and deficient ships recorded by PSC Officers for ships certified and classed by individual classification societies. The study estimated the average deficiency to inspection ratio (ADIR) and mean detention to inspection ratio (MDIR) for ships certified and classed by identified individual classification societies in the Abuja MoU regime. Secondary data covering the period between 2015 and 2020 sourced from the database of the Abuja MoU administration was used. The findings indicated that Germanischer Lloyds, CCS-China, KRS-Korea, NNK-Japan, RMRS-Russia, Lloyds Register, London, Bureau Veritas, Det Norsk Veritas, ABS-USA, and RINA-Italy have better performance with regards to maritime safety in the Abuja MoU regime, as shown by the MDIR scores. Thus, they dominated ship-owners’ preference for ship classification in West and Central African waters between 2015 and 2020. The trend of ship detention following compromised seaworthiness in the jurisdiction of the Abuja MoU on PSC for vessels certified by the International Naval Survey Bureau (INSB), CCS-China, Germanischer Lloyds (GL), International Register of Ships, Lloyds Register of Ships (LR), and NKK-Japan have negative coefficients of average rate of change, which indicates a decreasing trend in the number of vessels detained between 2015 and 2020; the rest of the classification societies, with positive coefficients of average rate of change, show an increasing trend in the number of ships detained for deficiencies that compromised seaworthiness; classified and registered by each classification society. Vessels classified by GL with ADIR of 0.034 (3.4 %) showed the least likelihood of having safety defaults and deficiency. It is recommended that the performance of poorly performing classification societies in upholding maritime safety standards should be improved. This implies that classification societies with average deficiency to inspection ratios (ADIR) of higher than 0.10 (10 %) should be reduced, while classification societies with mean detention to inspection ratios (MDIR) of 0.01 (1 %) and higher should be reduced.