These studies were carried out to understand the cloud formation behavior of nonionic surfactant Triton X-114 (1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol; t-Oct-C6H4-(OCH2CH2),OH, x = 7-8) in different aqueous media such as distilled water, Na-acetate, NaNO3, etc. The effects of organic dopents (often added for metal extractions) such as tributyl phosphate (TBP), n-dodecane, dibenzoylmethane (DBM), and thenoyltrifluoroacetone (HTTA) on cloud formation and metal ions (viz. U(VI), Am(III), Sr(II), and Cs(I)) extraction were also investigated. The cloud formation behavior was investigated visually, by spectrophotometry and by dynamic light scattering (DLS). For distilled water (DW) + 0.12% w/v Triton X-114 system (pH 5-6), the cloud point (CP) decreased with increase concentration of TBP (24 degrees C (no TBP) to similar to 5 degrees C (0.11 M TBP)). By contrast, the addition of n-dodecane in DW + 0.12% w/v Triton X-114, required higher temperature for cloud formation. Similar observations were made in 0.1 M Na-acetate and 0.1 M NaNO3 media. The CP was observed at 12 degrees C for 0.1 M Na-acetate + 0.12% w/v Triton X-114 system (pH 8) after the addition of 1 X 10(-4) M DBM (methanol). This suggests that the presence of polar molecules helps in the dehydration of hydrophilic ends of the surfactant. Spectrophotometric and DLS measurements also conformed to the visual method for identifying the CP for different samples. These measurements showed an abrupt increase in the absorbance or aggregate size at the cloud point. Extraction (%) of the metal ions using DBM and HTTA as extractants followed the order: U(VI) > Am(III) > Sr(II) > Cs(I).