The extraction of Fe(II), Fe(III), Mn(II), and Cr(III) with bis(2-methylylidene phenol) diaminoethane from various acid solutions have been studied. The light yellow Cr(III) and brown Mn(II) complexes have maximum absorption at 415nm and 405nm respectively while the reddish brown Fe(II) and light green Fe (III) complexes have maximum absorption at 445nm and 390nm respectively. Some effective parameters on extraction and complex formation, such as extraction solvent type and volume, equilibration time, effects of salt, diverse ions, temperature, masking agents, color stability, and acid concentrations have been optimized. Iron, manganese and chromium have been separated and determined in the presence of one another and of many other elements. The method was also successfully applied for the determination of Fe(II), Fe(III), Mn(II) and Cr(III) in the tap water and rain water with recoveries of 98-103% and RSD of less than 0.5%. The regression and ANOVA results shows that at 95% confidence level (p<0.05) the results as compared to other methods are statistically significant.