Yes — N'Djamena's city centre is navigable for informed travellers, but Chad as a whole carries a high-risk advisory from most Western governments, and visitors must exercise a high degree of caution at all times.
The main concerns are political instability (Chad has experienced multiple coups and ongoing Sahel insurgency pressure), petty crime in markets and around the airport, and the risk of civil unrest or demonstrations that can turn violent with little warning. Armed conflict remains active in border regions — particularly near Sudan, the Central African Republic, and Lake Chad — and travel to those areas is strongly discouraged without specialist security support.
In the city itself, practical measures significantly reduce risk: use radio-dispatched or hotel-recommended taxis rather than hailing vehicles on the street; avoid displaying expensive cameras or jewellery; carry a photocopy of your passport and visa; and stay aware of the news cycle, as political situations can shift quickly.
Register with your embassy on arrival, purchase comprehensive travel insurance that covers medical evacuation, and brief yourself on the location of your country's diplomatic mission before you land. Travelling with an established tour operator experienced in the Sahel region adds a substantial safety margin.