Introduction Christmas-themed scientific articles are becoming increasingly popular and may represent a shortcut to scientific demise due to their demand for time better spent on "serious" research. We aimed to investigate whether authorship on Christmas-themed medical articles could damage the scientific careers of authors. We hypothesized that Christmas-authorships had a negative impact on core bibliometric outcomes such as publication rates. Methods We extracted demographic and bibliometric data on first- and last authors of medical papers written for the Christmas edition of Journal of The Danish Medical Association through the years 2010-2012. These cases were compared with controls representing authors of original "serious" research papers written in the same years. We performed a negative binomial regression with the number of publications ten years after the index date (defined as the publication year of Christmas/"serious" article) as the outcome and adjusted models for sex and age. Results We found that first authors of Christmas-themed papers had a publication rate ratio (PRR) of 3.8 (95% confidence interval (CI): 1.4-12.4) in unadjusted analysis and last authors had a PRR of 0.6 (95% CI: 0.2-1.6). The associations weakened and were statistically insignificant in adjusted analyses. Conclusion Our results indicate that first authors publish more in the years following the publication of a Christmas article, although the association may be entirely driven by sex and age. Causality remains uncertain and further studies (such as RCTs) which randomize authors to produce Christmas-themed (preferably in a Santa's workshop setting) or serious articles are needed. Funding. None. Trial registration. None.