The study investigated the effect of environmental health services on students’ academic performance in secondary schools in Brass Local Government Area of Bayelsa State. The study adopted the descriptive survey design. The sample for the study comprised a total of 245 students and 59 teachers, amounting to 304 respondents. The instrument used was a researchers’ developed questionnaire titled, “Environmental Health Services and Students’ Academic Performance Questionnaire (EHSSAPQ)” which was validated by two experts in measurement and evaluation. Reliability of the instrument was established using Pearson Product Moment Correlation technique and a reliability coefficient of 0.71 was obtained. Four research questions and four hypotheses tested at 0.05 Alpha levels guided the conduct of the study. Data analysis was done using frequent count, percentages and chi-square. The result show that higher percentages of the respondents were of the opinion that portable water, drainage system and waste disposal do not affect students’ academic performance, except for first aid where teachers affirmed that it affected academic performance. The test of hypotheses revealed significant effects of portable water and first aid treatment on students’ academic performance with chi-square values of 4.00 and 16.23 respectively. Based on the findings, recommendations were made that portable water and first aid treatment be made available in schools.Keywords: Environmental health services, academic performance, secondary school