We synthesize previous findings and contribute to the redundancy debate on Machiavellianism and psychopathy from a longitudinal perspective, which accounts for the situational nature of Machiavellianism. We recruited 317 participants, who completed state measures of Machiavellianism and psychopathy for 30 days. Using multilevel confirmatory factor analysis we found the two-factor solution to be of better fit, compared to the single-factor model. Next, the connection between factors was weaker at the within-person level as compared to the between-person level. Finally, the pattern of fluctuations, investigated using Dynamic Structural Equation Modelling differentiated both constructs. While we acknowledge the concerns pertaining to Machiavellianism and psychopathy redundancy at the self-reported assessment level, we provide evidence of their distinguishability when their within-person trajectories are considered.