Senior School Certificate Examination (SSCE) is a standardised test conducted by three examination bodies in Nigeria: West African Examinations Council (WAEC), National Examinations Council (NECO) and National Business and Technical Examination Board (NABTEB). Test experts are interested in the equivalence of grades obtained in subjects taken by candidates across the different subjects. There is however a dearth of literature comparing results of different equating methods for examination bodies in Nigeria especially in SSCE Chemistry. This study was designed to investigate Levine linear and Chained equipercentile equating of Senior School Certificate Chemistry multiple-choice papers in South-west Nigeria. The objectives of the study were to: (i) examine studentsâ€™ performance on the common items of SSCE Chemistry Multiple-Choice papers; (ii) determine studentsâ€™ performance in the unique items; (iii) determine the results of Levine linear method of equating tests with the use of standard score deviates; (iv) determine the results of chained equipercentile method of equating tests with the use of percentile rank; and (v) examine the invariance of SSCE equated scores obtained by Levine linear and Chained equipercentile equating methods.rnThe research design adopted for the study was Non Equivalent Groups Anchor Test design. The study was carried out among 322,484 Senior Secondary III students in the South-west geopolitical zone of Nigeria. A sample of 1,461 students was selected using multi-stage sampling procedure. The 2017 WAEC, NECO and NABTEB SSCE multiple choice Chemistry papers were used as instruments for data collection. The WAEC, NECO and NABTEB papers yielded coefficients of content validity of 0.70, 0.67 and 0.69 and reliability of 0.81, 0.79 and 0.78 respectively. Data obtained were analysed using mean, standard deviation, standard score deviates of T-score, percentile rank and coefficient of variation.rnThe findings of this study were that:rni. mean performance of students on the common items of WAEC, NECO and NABTEB were 5.46, 6.04 and 7.36 respectively;rnii. mean performance of students in unique items across the test forms (WAEC, NECO and NABTEB) were 17.32, 18.03 and 20.48 respectively;rniii. the Levine linear method indicated that a score of 20 was found equivalent to scores of 20.17, 20.47 and 22.97 in WAEC, NECO and NABTEB respectively with a standard score deviate of 21;rniv. chained equipercentile score of 20 in WAEC was equivalent to scores of 20 and 23 in NECO and NABTEB respectively which corresponded to the percentile rank of 75; andrnv. levine linear equating yielded a coefficient of variation of 35.1% while chained equipercentile equating yielded 45.5%.rnThe study concluded that Levine linear equating was more efficient for equating of Chemistry SSCE scores. This implies that methods to be used for equating test scores should first be determined by test experts before equating. The study recommended that test developers should adopt the Levine linear equating method that yielded lower coefficient of variation in equating test scores in Chemistry multiple choice items.