Reactive sintering of 3Ti:Sn:2C and 3Ti:Sn:2C:0.6Fe powder mixtures is studied in the temperature range 510°C–1200°C under argon. It is demonstrated that the recently discovered Ti3SnC2 phase is formed, provided that Fe is added to a 3Ti:Sn:2C reactant mixture within the synthesis conditions used. Using dilatometric and X-Ray diffraction analyses, the formation mechanism of Ti3SnC2 is discussed. Results show that at low temperature (about 510°C), tin is consumed to form FexSny intermetallics. At high temperature (about 1060°C), tin is newly available to form Ti3SnC2 due to the melting of FexSny. Then, the intermediate phases, TiC and Ti2SnC, and/or Ti5Sn3, TiC, C, and Ti are dissolved in the (Fe + Sn) liquid phase and Ti3SnC2 very likely precipitate from the melt. The second part of the study deals with the optimization of the Fe content in the initial 3Ti:Sn:2C reactant powder mixture to synthesize samples with larger Ti3SnC2 content by hot isostatic pressing.