This study investigated how 4-month-old infants represent sequences: Do they track the statistical relations among specific sequence elements (e.g., AB, BC) or do they encode abstract ordinal positions (i.e., B is second)? Infants were habituated to sequences of 4 moving and sounding elements—3 of the elements varied in their ordinal position while the position of 1 target element remained invariant (e.g., ABCD, CBDA)—and then were tested for the detection of changes in the target’s position. Infants detected an ordinal change only when it disrupted the statistical co-occurrence of elements but not when statistical information was controlled. It is concluded that 4-month-olds learn the order of sequence elements by tracking their statistical associations but not their invariant ordinal position.