Abstract. In this paper we establish an intimate connection between dynamic range searching in the group model and combinatorial discrepancy. Our result states that, for a broad class of range searching data structures (including all known upper bounds), it must hold that tutq = Ω(disc 2 ) where tu is the worst case update time, tq the worst case query time and disc is the combinatorial discrepancy of the range searching problem in question. This relation immediately implies a whole range of exceptionally high and near-tight lower bounds for all of the basic range searching problems. We list a few of them in the following:• For d-dimensional halfspace range searching, we get a lower bound of tutq = Ω(n 1−1/d ). This comes within a lg lg n factor of the best known upper bound.• For orthogonal range searching, we get a lower bound of tutq = Ω(lg d−1 n).• For ball range searching, we get a lower bound of tutq = Ω(n 1−1/d ). We note that the previous highest lower bound for any explicit problem, due to Pǎtraşcu [STOC'07], states that tq = Ω((lg n/ lg(lg n + tu)) 2 ), which does however hold for a less restrictive class of data structures.Our result also has implications for the field of combinatorial discrepancy. Using textbook range searching solutions, we improve on the best known discrepancy upper bound for axis-aligned rectangles in all dimensions d ≥ 3.Key words. range searching, lower bounds, group model, discrepancy, computational geometry AMS subject classifications. 68P05,68Q171. Introduction. Range searching is one of the most fundamental and wellstudied topics in the fields of computational geometry and spatial databases. The input to a range searching problem consists of a set of n geometric objects, most typically points in d-dimensional space, and the goal is to preprocess the input into a data structure, such that given a query range, one can efficiently aggregate information about the input objects intersecting the query range. Some of the most typical types of query ranges are axis-aligned rectangles, halfspaces, simplices and balls.The type of information computed over the input objects intersecting a query range include for instance, counting the number of such objects, reporting them and computing the semi-group or group sum of a set of weights assigned to the objects.In the somewhat related field of combinatorial discrepancy, the focus lies on understanding set systems. In particular, if (Y, A) is a set system, where Y = {1, . . . , n} are the elements and A = {A 1 , . . . , A m } is a family of subsets of Y , then the minimum discrepancy problem asks to find a 2-coloring χ : Y → {−1, +1} of the elements in Y , such that each set in A is colored as evenly as possible, i.e. find χ minimizing disc ∞ (χ, Y, A), where