This study examined effect that school outdoor activities could have on senior secondary two students' retention in ecology in Jalingo metropolis of Taraba State. Non randomized pre test post test control group Quasi-experimental design was adopted. The population is 1,227 students from 13 co-educational schools in the study area. A sample of 160 SSII students from 4 co-educational schools was used. A 40 item Instrument called Biology Achievement Test (BAT) developed by the researchers with reliability co-efficient of 0.95 using Kunder-Richardson formula 21 was used for data collection. The schools were grouped into 2, the experimental group was taught using school outdoor activities while the control group was taught using lecture method. Intact classes were used in all the schools. Students were pre tested, treated for 6 weeks and retention test was administrated 4 weeks after completion of teaching exercise. Data collected were analysed using mean, standard deviation to answer two researcher questions while analysis of covariance (ANCOVA) was used to test the 3 hypotheses at 0.05 level of significance.