Urban farming practitioners face challenges like lack of quality irrigation water, poorly decomposed manure, diverse inputs of unknown sources, unhealthy farm environment and abject poverty. All these contribute to production of unsafe food. Heavy metals and pathogens contaminate edible produce like tomato fruits, kale leaves and arrowroot corms. Urban produced vegetable crop contamination can come from substrates, irrigation water or the atmosphere. Therefore, this study was conducted to evaluate the features of urban farming in Nairobi city. Predesigned semi structured questionnaires were administered to ninety five farmers in eight of the nine Nairobi districts. Forty two percent of Nairobi farmers irrigate used city council supplied water with 16 and 7.4% using waste water (including sewage) and polluted stream water, respectively. County council supplied water was used by over 70% of degree holders with none using sewage water. Fourteen percent of farmers with primary level education used sewage. Out sourced livestock manure was used by 41.1% of the farmers, 21.1% from on-farm livestock while 12.6% used compost. Youths and over 65 year old farmers had half of their population using out sourced and own livestock manure, respectively. Agricultural waste is fed to livestock by 45.3% of farmers, 35.8% recycle and 3% throw it away. The highest users of county council supplied water for irrigation are the degree holders at 70% implying that the level of education greatly contributes to ultimate food safety.