Using　flexible　neuromorphic　electronics　that　emulate　biological　neuronal　systems　is　an　innovative　approach　for　facilitating　the　implementation　of　next-generation　artificial　intelligence　devices,　including　wearable　computers,　soft　robotics　devices,　and　neuroprosthetics.　Stretchable　synaptic　transistors　based　on　field-effect　transistors　(FETs),　which　have　functions　and　structures　resembling　those　of　biological　synapses,　are　promising　technological　devices　in　flexible　neuromorphic　electronics　owing　to　their　high　flexibility,　excellent　biocompatibility,　and　easy　processability.　However,　obtaining　stretchable　synaptic　FETs　with　various　synaptic　characteristics　and　good　stretching　stabilities　is　challenging.　Significant　efforts　to　produce　stretchable　synaptic　FETs　have　been　undertaken,　and　remarkable　advances　in　materials,　fabrication　processes,　and　applications　have　been　achieved.　From　this　perspective,　we　discuss　the　requirements　for　neuromorphic　devices　in　flexible　neuromorphic　electronics　and　the　advantages　of　stretchable　synaptic　FETs.　Moreover,　representative　methods　used　to　implement　stretchable　synaptic　transistors,　including　the　structural　design　and　development　of　intrinsically　stretchable　devices,　are　introduced.　Additionally,　the　application　of　stretchable　synaptic　transistors　in　artificial　sensory　systems　such　as　light,　tactile,　and　multisensory　artificial　nervous　systems　is　also　discussed.　Finally,　we　highlight　the　possible　challenges　in　implementing　and　using　stretchable　synaptic　transistors,　propose　solutions　to　overcome　the　current　limitations　of　these　devices,　and　suggest　future　research　directions.　©　The　Author(s)　2023.