Rank annihilation factor analysis (RAFA) was used for the spectrophotometric studies of complex formation between a new Schiff base derived from 3,6-bis((aminoethyl)thio)pyridazine and some transition metals in dimethylformamide (DMF). Formation constants of these complexes were derived using RAFA on spectrophotometric data. According to molar ratio data and Job's plot, the stoichiometry of complexation between the Schiff base and the Nil(2+), Co(2+), Cu(2+), and Zn(2+) cations was 1:1 and for Pd(2+) was 2:1. The logarithm of the complex formation constants was found to be 5.66 for Ni(2+), 5.1 for Co(2+), 7.08 for Cu(2+), 6.73 for Zn(2+), and 7.77 for Pd(2+).