A farm level sustainability indicator was determined within the framework of small-scale farming households utilizing Fadama for the cultivation of horticultural crops in the Southern Guinea Savanna of Nigeria. The study determined Indicators of Sustainable Agricultural Practices (ISAP) and identifies the critical farming practices to monitor in order to sustain productivity of Fadama land. A two- stage simple random sampling technique was used to obtain 180 horticultural crops producing households interviewed for the study. The data were collected for 2008 cropping season. The data were analyzed with descriptive statistics such as frequency distribution, mean, standard deviation, scoring and weighting of farm practices and sustainability web. The Indicator of Sustainable Agricultural Practices (ISAP) mean score of 0.622 implied that crop production practices of sampled farming households were fairly sustainable. The study showed that methods of pest control, weed control, and soil fertility maintenance were the critical indices to monitor for the improvement of sustainability. In order to ensure sustainability of Fadama for horticultural crops production the study recommends increased, integrated pest management and regulated use of agro-chemical.