Aim of Study To measure Retinal nerve fiber layer (RNFL) thickness among adult Nigerians in order to establish a normative database. Methods and Materials The study involved 120 adult Nigerians, of various tribes, aged 18 years and above who met the selection criteria and gave their consent for participation. They had dipstick urinalysis and blood pressure measurements. They then underwent detailed ophthalmic evaluation including best corrected visual acuity, anterior and posterior segment examination and intraocular pressure measurements. Topcon 3D Optical Coherence Tomography (OCT) 1 Maestro was used to take RNFL thickness measurements using the 3D optic nerve head analysis under glaucoma protocol. Results The average RNFL thickness of the 120 adult Nigerians was 111.49 ± 9.06µm.The mean inferior retina was thickest at 149.06±14.94 µm, the superior was 142.25± 13.67 µm, the nasal was 83.30 ±13.26 µm and the temporal was 70.03 ±9.65 µm. There was significant asymmetry between the right eye value of 112.33 ± 9.60µm and left eye of 110.59± 9.14µm, (p<0.001). There was no significant gender difference. The Igbo tribe had the highest value of 116.27 ± 7.15 µm while the Hausa/Fulani had the least average RNFL of 108.29 ± 8.88µm.