The use of agricultural marginal lands like riparian areas for arable cropping is now rampant and fast spreading across global communities. Ironically, stream bank cultivation is institutionally illegal but it is practically condoned among local people thereby raising controversy over its sustainability. The study assessed the environmental costs and benefits of riverbank cultivation along a middle section of Chiredzi river in Zimbabwe. Riparian buffer zones were created along the middle section of Chiredzi river satellite image and transect walks were done for ground truthing during the period 10 - 24 August 2016. This data was corroborated with responses from 84 questionnaire respondents, participatory rural appraisal and 8 key informants interviews. Both qualitative and quantitative data analyses yielded informative results. Cultivation of riparian areas was attributed to local land pressures, fertile alluvial soils with higher and longer moisture regimes, higher agricultural productivity, recurrent drought mitigation and closeness to a constant water source among other pressures and benefits. However, river and dam siltation and their subsequent drying up, were among noted environmental challenges. The paper recommends that traditional and government institutions should collaborate to avail and buttress adaptive and sustainable conservation agriculture to rural farmers to minimize riparian environmental degradation and guarantee secure livelihoods for the rural poor.