Available evidence on the impact of ovarian stimulation on the progression of endometriosis or its recurrence was systematically reviewed. Data from ovarian stimulation alone, or associated with intrauterine insemination (IUI) or IVF, were included. Sixteen studies were selected. Initial case reports (n = 11) documented some severe clinical complications. However, subsequent observational studies were more reassuring. Overall, five conclusions can be drawn: (i) IVF does not worsen endometriosis-related pain symptoms (moderate quality evidence); (ii) IVF does not increase the risk of endometriosis recurrence (moderate quality evidence); (iii) the impact of IVF on ovarian endometriomas, if present at all, is mild (low quality evidence); (iv) IUI may increase the risk of endometriosis recurrence (low quality evidence); (v) deep invasive endometriosis might progress with ovarian stimulation (very low quality evidence). In conclusion, available evidence is generally reassuring (at least for IVF) and does not justify aggressive clinical approaches such as prophylactic surgery before assisted reproductive technology treatment to prevent endometriosis progression or recurrence. However, further evidence is required before being able to reach definitive conclusions. In particular, the potential effects on deep invasive endometriosis and the possible synergistic effect of stimulation and pregnancy are two areas that need to be explored further.