OBJECTIVES To document biomedical paper titles containing literary and other allusions. DESIGN Retrospective survey. SETTING Medline (1951 to mid-2005) through Dialog Datastar. MAIN OUTCOME MEASURE Allusions to Shakespeare, Hans Christian Andersen, proverbs, the Bible, Lewis Carroll, and movie titles, corrected and scaled for five year periods 1950-4 to 2000-4. RESULTS More than 1400 Shakespearean allusions exist, a third of them to "What's in a name" and another third to Hamlet-mostly to "To be or not to be." The trend of increasing use of allusive titles, identified from Shakespeare and Andersen, is paralleled by allusions to Carroll and proverbs; the trend of biblical allusions is also upward but is more erratic. Trends for newer allusions are also upwards, including the previously surveyed "paradigm shift." Allusive titles are likely to be to editorial or comment rather than to original research. CONCLUSIONS The similar trends are presumably a mark of a particular learnt author behaviour. Newer allusions may be becoming more popular than older ones. Allusive titles can be unhelpful to reviewers and researchers, and many are now clichés. Whether they attract readers or citations is unknown, but better ways of gaining attention exist.