Abstract:We present a method to obtain both exact values and sharp estimates for the total variation distance between binomial and Poisson distributions with the same mean λ. Concerning exact values, we give an easy formula which holds for moderate sample sizes n, provided that λ is neither close to l + √ l from the left, l = 1, 2, . . ., nor close to m − √ m from the right, m = 2, 3, . . .. Otherwise, a simple efficient algorithm is provided. The zeroes of the second Krawtchouk and Charlier polynomials play a fundamental role.