This document describes the construction of new three-step and five-step block linear multistep methods for solving stiff initial value problems. The methods are derived using interpolation and collocation procedures. The three-step method is of uniform order four, while the five-step method is of uniform order six. Stability analysis shows that the methods are A-stable, consistent, and zero stable. Numerical results demonstrate that the new block methods compete favorably with MATLAB's ODE solver for stiff problems.