Based on a large number of toxicity studies of single chemicals and complex mixtures, a set of four toxicity tests utilizing amphibian embryos (AMPHITOX) was developed (Herkovits and Pérez-Coll 1999). In this contribution, the versatility of AMPHITOX for the evaluation of the toxicity in 36 environmental samples is reported. AMPHITOX can be customized to acute (AMPHIACUT), short-term chronic (AMPHISHORT), and chronic (AMPHICHRO) exposure periods. By plotting the LC₁₀ (or NOEC), LC₅₀ and LC₉₀ (or LC₁₀₀), the toxicity profile (TOP) curves from 24 hr to 14 days of exposure can be obtained allowing the visualization of concentration- and time-exposure thresholds, as well as the range of concentrations which exerts adverse effects in each case. By employing the early-life-stage test (AMPHIEMB) it is also possible to evaluate malformations. The environmental samples studied were obtained from surface and ground water, leaches, industrial effluents and soils. Data from acute, short-term chronic and chronic tests, were expressed as LC₅₀-96 h, NOEC 168 h (7 days) and NOEC 336 h (14 days). The maximal value for acute toxicity was 0.5 % V/V (in a leach), while the lower toxicity was 85 % V/V corresponding to the NOEC/14 days for a leach sample. In 6 samples (4 provided from reference places) no toxicity was detected. By applying the AMPHIEMB test in a water sample providing from Gutierrez stream in Lujan, Buenos Aires Province, 100 % lethality with concentrations over 50 % within 7 days of exposure was obtained and the surviving embryos exhibited reduced body size, delayed development and malformations. Malformations including microcephaly, abnormally developed tail and severe flexures, were proportional to the concentration of the sample. The results point to the possibility of evaluating the toxicity of a wide diversity of environmental samples. This may be accomplished by selecting the most appropriate AMPHITOX test according to the toxicity of the sample and the end point of major relevance. Ultimately amphibian embryos can be used in toxicity studies as indicators of environmental quality for wildlife protection purposes.