diff --git a/src/OpenTelemetry.Api/CHANGELOG.md b/src/OpenTelemetry.Api/CHANGELOG.md
index 723c81e61d4..40731931f75 100644
--- a/src/OpenTelemetry.Api/CHANGELOG.md
+++ b/src/OpenTelemetry.Api/CHANGELOG.md
@@ -6,6 +6,9 @@
   ([#1415](https://github.com/open-telemetry/opentelemetry-dotnet/pull/1415))
 * Removed `IsOk` property from `Status` and fixed `StatusCode` enum values
   ([#1414](https://github.com/open-telemetry/opentelemetry-dotnet/pull/1414))
+* `B3Propagator` now supports the value `true` to be passed in for the header
+ `X-B3-Sampled`.
+ ([#1413](https://github.com/open-telemetry/opentelemetry-dotnet/pull/1413))
 
 ## 0.7.0-beta.1
 
diff --git a/src/OpenTelemetry.Api/Context/Propagation/B3Propagator.cs b/src/OpenTelemetry.Api/Context/Propagation/B3Propagator.cs
index 0b30c32c4f6..73f7677f19e 100644
--- a/src/OpenTelemetry.Api/Context/Propagation/B3Propagator.cs
+++ b/src/OpenTelemetry.Api/Context/Propagation/B3Propagator.cs
@@ -40,14 +40,19 @@ public sealed class B3Propagator : IPropagator
         // ActivityTraceId.SIZE hex characters (8-bytes traceId) in the past.
         internal const string UpperTraceId = "0000000000000000";
 
-        // Sampled value via the X_B3_SAMPLED header.
+        // Sampled values via the X_B3_SAMPLED header.
         internal const string SampledValue = "1";
 
+        // Some old zipkin implementations may send true/false for the sampled header. Only use this for checking incoming values.
+        internal const string LegacySampledValue = "true";
+
         // "Debug" sampled value.
         internal const string FlagsValue = "1";
 
         private static readonly HashSet<string> AllFields = new HashSet<string>() { XB3TraceId, XB3SpanId, XB3ParentSpanId, XB3Sampled, XB3Flags };
 
+        private static readonly HashSet<string> SampledValues = new HashSet<string>(StringComparer.Ordinal) { SampledValue, LegacySampledValue };
+
         private readonly bool singleHeader;
 
         /// <summary>
@@ -180,7 +185,7 @@ private static PropagationContext ExtractFromMultipleHeaders<T>(PropagationConte
                 }
 
                 var traceOptions = ActivityTraceFlags.None;
-                if (SampledValue.Equals(getter(carrier, XB3Sampled)?.FirstOrDefault(), StringComparison.Ordinal)
+                if (SampledValues.Contains(getter(carrier, XB3Sampled)?.FirstOrDefault())
                     || FlagsValue.Equals(getter(carrier, XB3Flags)?.FirstOrDefault(), StringComparison.Ordinal))
                 {
                     traceOptions |= ActivityTraceFlags.Recorded;
@@ -239,7 +244,7 @@ private static PropagationContext ExtractFromSingleHeader<T>(PropagationContext
                 if (parts.Length > 2)
                 {
                     var traceFlagsStr = parts[2];
-                    if (SampledValue.Equals(traceFlagsStr, StringComparison.Ordinal)
+                    if (SampledValues.Contains(traceFlagsStr)
                         || FlagsValue.Equals(traceFlagsStr, StringComparison.Ordinal))
                     {
                         traceOptions |= ActivityTraceFlags.Recorded;
diff --git a/test/OpenTelemetry.Tests/Trace/Propagation/B3PropagatorTest.cs b/test/OpenTelemetry.Tests/Trace/Propagation/B3PropagatorTest.cs
index e24b9ae2da9..fb430b6f1b0 100644
--- a/test/OpenTelemetry.Tests/Trace/Propagation/B3PropagatorTest.cs
+++ b/test/OpenTelemetry.Tests/Trace/Propagation/B3PropagatorTest.cs
@@ -81,23 +81,28 @@ public void ParseMissingSampledAndMissingFlag()
             Assert.Equal(new PropagationContext(spanContext, default), this.b3propagator.Extract(default, headersNotSampled, Getter));
         }
 
-        [Fact]
-        public void ParseSampled()
+        [Theory]
+        [InlineData("1")]
+        [InlineData("true")]
+        public void ParseSampled(string sampledValue)
         {
             var headersSampled = new Dictionary<string, string>
             {
-                { B3Propagator.XB3TraceId, TraceIdBase16 }, { B3Propagator.XB3SpanId, SpanIdBase16 }, { B3Propagator.XB3Sampled, "1" },
+                { B3Propagator.XB3TraceId, TraceIdBase16 }, { B3Propagator.XB3SpanId, SpanIdBase16 }, { B3Propagator.XB3Sampled, sampledValue },
             };
             var activityContext = new ActivityContext(TraceId, SpanId, TraceOptions, isRemote: true);
             Assert.Equal(new PropagationContext(activityContext, default), this.b3propagator.Extract(default, headersSampled, Getter));
         }
 
-        [Fact]
-        public void ParseZeroSampled()
+        [Theory]
+        [InlineData("0")]
+        [InlineData("false")]
+        [InlineData("something_else")]
+        public void ParseNotSampled(string sampledValue)
         {
             var headersNotSampled = new Dictionary<string, string>
             {
-                { B3Propagator.XB3TraceId, TraceIdBase16 }, { B3Propagator.XB3SpanId, SpanIdBase16 }, { B3Propagator.XB3Sampled, "0" },
+                { B3Propagator.XB3TraceId, TraceIdBase16 }, { B3Propagator.XB3SpanId, SpanIdBase16 }, { B3Propagator.XB3Sampled, sampledValue },
             };
             var activityContext = new ActivityContext(TraceId, SpanId, ActivityTraceFlags.None, isRemote: true);
             Assert.Equal(new PropagationContext(activityContext, default), this.b3propagator.Extract(default, headersNotSampled, Getter));