AIM: This is an Optical Coherence Tomography study aimed at determining the correlation between retinal nerve fiber layer thickness and vertical cup disc ratio in glaucoma suspects in the University of Port Harcourt teaching hospital, Port Harcourt. MATERIALS AND METHODS: This is a non-intervention observational hospital based study using consecutive allocation of glaucoma suspects as they presented to the glaucoma clinic between October 2nd , 2012 and January 31st 2013.Observations were done using the Optical Coherence Tomography machine . Data was analyzed using the statistical package EPI info version 6.04d, a software package designed by the Centers For Disease Control and Prevention(CDC),USA in 2001. RESULTS: A total of 120 participants comprising 60males (50%) and 60 females (50%) were examined with a mean age of 42.8±13.79, the age range was 19 to 75 years. The retinal nerve fiber layer was noticed to be thickest in the inferior quadrant, followed by the superior, nasal and temporal quadrants. Age was noticed to increase with decreasing RNFL thickness ( p < 0.05; r = - 0.38 ) Optic disc diameter increased with increasing RNFL thickness (p < 0.05; r = 0.18 ) Vertical cup disc ratio increased with decreasing RNFL thickness ( p< 0.05 ; r = - 0.21), although poorly correlating. Disc size was noticed to increase with increasing VCDR with a weak positive correlation. CONCLUSION: There was a weak negative correlation between age and the retinal nerve fiber layer thickness in the subjects, There was also a weak positive correlation between the optic disc diameter and the retinal nerve fiber layer thickness of the subjects, such a correlation may be the result of either an increased number of nerve fibers in eyes with larger discs or a smaller distance between the circular scan and the true optic disc margin. There was no strong correlation between vertical cup disc ratio and retinal nerve fiber layer thickness among the glaucoma suspects. Vertical cup disc ratio therefore should not be used to estimate the extent or degree of retinal nerve fiber layer loss.