The release of radionuclides during nuclear accidents poses significant environmental risks, with cesium being one of the most critical due to its radiological hazards and potential impacts on agriculture. This study aims to monitor and predict the uptake and fate of radioactive cesium in soils and plants within a Moroccan semi-arid agricultural ecosystem using controlled pot experiments. Soil samples were collected from a semi-arid region in Rabat-Salé. The study involved a diverse range of plants, including carrots, beets, broad beans, green beans, mint, coriander, radishes, zucchini, barley, soft wheat, garlic, celery, parsley, cauliflower, green peppers, and tomatoes. Pots were maintained in a greenhouse under controlled temperature and periodically irrigated. Samples from roots, shoots, flowers, stems, and grains (or seeds) were collected and analyzed by ICP–Mass Spectrometry. The results show that in cereals, soft wheat accumulates more Cs-133 in the roots (TF = 1.14) than in the stems and shoots (TF = 0.08), indicating preferential retention in the root system. Leafy vegetables displayed strong variability: parsley showed extremely high root accumulation (TF = 42.45), while mint accumulated Cs-133 mainly in leaves and stems (TF = 19.93). Conversely, species such as coriander and celery exhibited moderate and more evenly distributed transfer coefficients. Among non-leafy vegetables, zucchini exhibited high Cs-133 accumulation in roots (TF = 20.13), whereas tomato showed very low uptake in all tissues (TF < 0.1). For legumes, white bean showed moderate accumulation in leaves, roots, and stems, but a very high transfer to seeds (TF = 32.36). Finally, among root crops, radish displayed exceptionally high transfer to leaves (TF = 34.9) despite low root uptake (TF = 0.62), while beet and carrot also showed notable transfer, primarily to aerial parts. These findings highlight significant interspecific variability in cesium uptake and translocation, providing essential insights for predicting contamination pathways and guiding remediation strategies in semi-arid agricultural systems.