Memory is a key cognitive variable in pain management. This study examined the effect of headaches on participants' encoding of words (attention) and later memory for words. The dependent measures were response time during encoding and recognition memory; headache pain was the independent measure. Eighty participants were randomized to one of four groups: two groups had the same condition (headache pain or no headache pain) for both the encoding and memory tasks and two groups had mixed conditions (i.e. pain during encoding/no pain during recognition; no pain during encoding/pain during recognition). Participants with pain during encoding judged words significantly slower (177.53ms) than participants without pain during encoding. Participants with pain during the memory task recognized significantly fewer words (5.4%) than participants without pain during the memory task, regardless of pain condition during encoding. Results from this and other pain and memory studies conducted in this laboratory suggest that pain, as it adversely affects memory, may operate at a threshold level rather than on a dose-response continuum.