SUMMARY This was a tertiary hospital-based descriptive cross-sectional study on effective diagnostic tools for early detection of glaucoma in Lagos state. The study was designed to determine the validity of intraocular pressure measurement, pachymetry, and fundoscopy individually and in combination with each other in the detection of glaucoma using visual field as the gold standard. One hundred and forty-six newly referred adult patients of the General Eye Outpatient Clinic were selected through a systematic random sampling with no bias for sex or ethnicity using a structured questionnaire for data collection. The variables obtained for data analysis include; Socio-demographic characteristics, visual acuity, pupil reflex, family history of glaucoma, chronic diseases such as hypertension and diabetes, intraocular pressure, cup-disc ratio and central visual field. The data obtained were analysed with EPI-INFO 2008 statistical software. Frequencies and means were generated to observe pattern of variable distribution among the patients. Logistic regressions (Bivariate and Multivariable) and Spearman’s rank correlation coefficient were used to examine predictive values and correlation between variables respectively. Sensitivity and Specificity of tools determined and the likelihood ratios were obtained from Receiver Operating Characteristic curve for each tool. Out of the 292eyes of 146 selected patients, 192(65.75%) were negative to the diagnosis of glaucoma. Sixty-two (21.24%) eyes were confirmed as definite glaucoma, while 38(13.01%) eyes were classified as glaucoma suspect requiring further evaluation. Factors associated with glaucoma were advanced age (p=0.04 within 95%CI), family history of glaucoma (p<0.001 within 95% CI) and cup-disc ratio of ≥ 0.8 (p<0.001 within 95%CI and positive predictive value of 0.46).The right eye appears to have a higher probability of developing glaucoma earlier compared with the left eye (Receiver’s Operating Characteristics curve with higher likelihood ratio among tools). The cup-disc ratio appears to be a better diagnostic tool for glaucoma since it gives the best predictive value (0.46) and likelihood ratio of 46.31 with optimal cut-off point of 0.8 than all other variables. Therefore all cadres of eye care workers should develop a high index of suspicion for early diagnosis of glaucoma based on fundoscopy and then use the sensitive and specific diagnostic tools of perimetry, tonometry and pachymetry to confirm their suspicion.