AbstractA control algorithm which has been acclaimed as the best algorithm for a real system may not be the best algorithm for a different real system. Therefore, various self‐tuning algorithms for real distillation columns have been evaluated, in order to compare their performances. A variable forgetting factor algorithm is modified using a filter which permits the employment of one instead of two covariance matrices for distillation control. A cautious self‐tuning control of SISO system is extended to MIMO system of distillation control. Multivariable self‐tuning regulator, multivariable self‐tuning controller and multivariable cautious self‐tuning controller are implemented with modified variable forgetting factor for linear transfer function model, Waller et al. column, and rigorous non‐linear model, Wood and Berry column. For distillation control, a multivariable cautious self‐tuning algorithm with modified variable forgetting factor is much simpler than earlier reported algorithms. This has produced better results and demonstrated its effectiveness, even in the presence of noise when other adaptive controllers give unsatisfactory performance.