The article scrutinises how Germany’s non-political party radical left has discussed immigration and ‘cultural’ or ‘national’ identity in the context of past and current immigration into Germany, with a focus on the refugee crisis of 2015. Three types of radical left discourse are identified. First, some in the radical left have come to regard immigrants, in particular refugees, as an ‘ersatz proletariat’ and therefore as potential revolutionary instruments for their own project. Second, some agree that revolutionary change is necessary but subordinate their principles to practical support for immigrants and refugees in the here and now. Third, given the improbability of communist revolution and the crisis of ‘Western modernity’, some on the radical left have called for the defence of ‘the West’ and to help immigrants assimilate into Western civilisation. The article makes a timely contribution to the knowledge about contemporary radical left politics in Germany and shows the fractured nature of Germany’s non-political party radical left in the context of the refugee crisis. It also investigates the impact of ‘crisis’ as an ‘open moment’ and ‘catalyst’ on the radical left’s discourse-as-practice.