Biochemical analyses and auxin and cytokinin bioassays were performed to test the biological activity of wormcasts. Both cellulose paper pulp and soil casts ofLampito mauritii were rich in ammonia, urea, organic carbon content, organic matter, soluble phosphorus and ionic potassium levels. The total nitrogen content of the soil remained unaffected by worm activations. The casts ofLampito mauritii, Pheretima elongata, Pontoscolex corethrurus andOcnerodrilus occidentalis had greater urea levels relative to ammonia levels in contrast to those ofDrawida barwelli, Octochaetoides beatrix andPerionyx excavatus. Worm activations of the leaf compost amended-soils by these species reduced the total phenol levels to varying degree depending on the species examined. Aging and exposures to light reduced the activity levels of these plant growth promotors in the casts ofL. mauritii. A positive correlation between the worm density at the site of soil sampling and the plant growth promotor levels in the samples was obtained. The origin of these promotors from the gut microflora of the worm and their subsequent release into the environment were discussed.