This paper investigates the causal impact of childbirth on women’s likelihood of informal employment in Russia using twenty years of RLMS. We apply an event study framework following Kleven et al. (2019) to quantify child penalties in labour market outcomes and whether women are more likely to find themselves working informally following the birth of their first child. We find that childbirth significantly increases the probability of informal employment for women. The rise in informality is concentrated in only the first year after childbirth. For first-time mothers this transition is largely involuntary. Our findings align with recent evidence on Russia’s relatively integrated but segmented informal labour market (Bargain et al. 2021).