NCRB (National Crime Records Bureau) annual crime data consistently shows Gurugram with lower rates of reported violent crime than Delhi across multiple years. This is publicly available in the NCRB Crime in India reports. The comparison is directionally clear, though absolute numbers are not directly comparable given the population difference.
For expats, the city-level comparison is less useful than the society-level comparison. A gated community in GCER with 24-hour guards and CCTV is not meaningfully different in personal safety terms from a gated DLF colony in Vasant Kunj or Saket. The real decision is whether to live in a controlled-access compound — which both cities offer — rather than which city is "safer."
Where Gurugram is practically better for expats: emergency hospital access is faster from GCER to Medanta (12–15 minutes) than from most South Delhi residential areas to a comparable hospital. Traffic density in the GCER residential sectors is lower than in South Delhi during peak hours. The road quality on Golf Course Extension Road is significantly better than South Delhi residential roads. The trade-off is that Gurugram has fewer walkable public spaces, and Old Gurgaon (Sectors 10–15) is not an expat-friendly area in the way that parts of South Delhi are.