The　initial　stage　of　silver　electrodeposition　on　a　glassy　carbon　electrode　from　a　cyanide-free　bath　with　2-hydroxypyridine　(2-HP)　as　the　complexing　agent　is　studied.　The　influence　of　polyethyleneimine　(PEI)　as　an　additive　on　the　nucleation　and　growth　of　silver　are　also　examined.　Progressive　nucleation　mechanism　is　found　for　silver　deposition　according　to　Scharifker-Hills＇　model　with　three-dimensional　diffusion-　controlled　growth　nucleation.　This　mechanism　cannot　be　influenced　by　adding　PEI.　However,　the　diffusion　coefficient　of　the　silver-2-HP　complexes　and　the　density　of　nuclei　exhibit　a　remarkable　decrease　with　the　addition　of　PEI.　Smoother　and　brighter　silver　deposits　with　progressive　nucleation　features　were　obtained　in　the　presence　of　PEI　from　the　images　of　scanning　electron　microscopy.　©　2009　Elsevier　B.V.　All　rights　reserved.