diff --git a/src/spectator/formatting/profile_block.cr b/src/spectator/formatting/profile_block.cr
new file mode 100644
index 0000000..d17cf86
--- /dev/null
+++ b/src/spectator/formatting/profile_block.cr
@@ -0,0 +1,28 @@
+module Spectator::Formatting
+  # Contents of a profile block.
+  private struct ProfileBlock
+    # Creates the block.
+    def initialize(@profile : Profile)
+    end
+
+    # Appends the block to the output.
+    def to_s(io)
+      io.puts(ProfileSummary.new(@profile))
+
+      indent = Indent.new(io)
+      indent.increase do
+        @profile.each do |result|
+          entry(indent, result)
+        end
+      end
+    end
+
+    # Adds a result entry to the output.
+    private def entry(indent, result)
+      indent.line(result.example)
+      indent.increase do
+        indent.line(SourceTiming.new(result.elapsed, result.example.source))
+      end
+    end
+  end
+end
diff --git a/src/spectator/formatting/profile_summary.cr b/src/spectator/formatting/profile_summary.cr
new file mode 100644
index 0000000..9d6a05c
--- /dev/null
+++ b/src/spectator/formatting/profile_summary.cr
@@ -0,0 +1,29 @@
+module Spectator::Formatting
+  # Top line of a profile block which gives a summary.
+  private struct ProfileSummary
+    # Creates the summary line.
+    def initialize(@profile : Profile)
+    end
+
+    # Appends the summary to the output.
+    def to_s(io)
+      io << "Top "
+      io << @profile.size
+      io << " slowest examples ("
+      io << human_time
+      io << ", "
+      io.printf("%.2f", percentage)
+      io << "% of total time):"
+    end
+
+    # Creates a human-friendly string for the total time.
+    private def human_time
+      HumanTime.new(@profile.total_time)
+    end
+
+    # Percentage (0 to 100) of total time.
+    private def percentage
+      @profile.percentage * 100
+    end
+  end
+end
diff --git a/src/spectator/formatting/source_timing.cr b/src/spectator/formatting/source_timing.cr
new file mode 100644
index 0000000..527fa17
--- /dev/null
+++ b/src/spectator/formatting/source_timing.cr
@@ -0,0 +1,16 @@
+module Spectator::Formatting
+  # Produces the timing line in a profile block.
+  # This contains the length of time, and the example's source.
+  private struct SourceTiming
+    # Creates the source timing line.
+    def initialize(@span : Time::Span, @source : Source)
+    end
+
+    # Appends the source timing information to the output.
+    def to_s(io)
+      io << HumanTime.new(@span).colorize.bold
+      io << ' '
+      io << @source
+    end
+  end
+end
diff --git a/src/spectator/formatting/suite_summary.cr b/src/spectator/formatting/suite_summary.cr
index be900f5..3d2dcfd 100644
--- a/src/spectator/formatting/suite_summary.cr
+++ b/src/spectator/formatting/suite_summary.cr
@@ -40,7 +40,7 @@ module Spectator::Formatting
 
     # Produces the profiling section of the summary.
     private def profile(profile)
-      raise NotImplementedError.new("profile")
+      @io.puts ProfileBlock.new(profile)
     end
 
     # Produces the statistical section of the summary.