Objective In our prior (first) study, suicide attempts were associated with the menses. The main hypothesis of this replication (second) study is that the proportion of suicide attempters during the menses is significantly higher than the expected probability in the general population. Methods Using the same methodology and setting, this replication naturalistic study included 120 fertile female suicide attempters with regular menstrual cycles during a 1-year period in the emergency room of a general hospital in Madrid, Spain, serving a catchment area of 500,000 people. Results The significant increase in probability of attempting suicide during the menses for the first study was 1.61; for the second study, 1.72; and for both studies combined, 1.68 (95% confidence interval, 1.27–2.09). Thus, using the combined results, the probability of attempting suicide during the menses was 1.68 times higher than the overall probability of attempting suicide for any fertile women. In the catchment area, the population rate of fertile women arriving at the hospital after a suicide attempt was 166 per 100,000. The probability for women during the menses arriving at the hospital after a suicide attempt was significantly higher, 279 per 100,000 (1.68 × 166 per 100,000). The 95% confidence interval was 211 to 347 per 100,000. Conclusions Despite inherent limitations, this naturalistic study replicates a small but significant increase of suicide attempts during the menses.