The study investigated the influence of students' gender on their understanding, application and analysis of Light waves concept in physics in Ikwerre Local Government Area of Rivers State, Nigeria. A quasi-experimental pretest-posttest design comprising of three experimental and one control group was used, each group was taught with a different Instructional method. A purposively selected sample of fifty-five (55) physics students of Senior Secondary 2 (SS2) class was involved in the study. Two instruments--Mathematics Ability Test (MAT) and Physics Performance Test on Light Waves (PPTLW)--with reliability coefficients of 0.97 and 0.89, respectively were used. The performances of the students were considered at the levels of understanding, application and analysis of Light waves. Data collected was analysed using mean scores and percentages for the research questions, while 4x2 Multivariate Analysis of Covariance was used to test the hypotheses. Analysis of results showed that demonstration method stands out as an effective method in bridging gender gap in the learning of difficult physics concepts like light waves. Furthermore, a significant difference was found between the performance of male and female students in the application of light waves while there was no significant difference between the performance of male and female students in the understanding and analysis of light waves.The post hoc analysis indicates that male students taught using guided-discovery method contributed more to the significant difference between the performance of male and female students in the application of light waves.